X-Git-Url: https://git.cworth.org/git?p=scherzo;a=blobdiff_plain;f=scherzo.c;h=665795977fcf4e2d5c9d397fe3b1579cab9af3ba;hp=6a5f2b3176c7f441fdf097714746705a74a91a2c;hb=e61e2b33d79fd2c55521ef46432ef3c40f3efc5b;hpb=aae6b7f55870ab7f9cd41f95e22231e66a673aea

diff --git a/scherzo.c b/scherzo.c
index 6a5f2b3..6657959 100644
--- a/scherzo.c
+++ b/scherzo.c
@@ -66,7 +66,6 @@ typedef struct scherzo
      * keyboard". Any "piano keyboard" key knows its own octave and
      * accidental already. */
     int keyboard_octave;
-    pitch_accidental_t keyboard_accidental;
 
     int midi_fd;
     snd_midi_event_t *snd_midi_event;
@@ -78,6 +77,8 @@ typedef struct scherzo
     pitch_group_t notes_pedaled;
 
     int pedal_pressed;
+
+    scherzo_key_t key;
 } scherzo_t;
 
 /* Forward declarations. */
@@ -94,10 +95,10 @@ static void
 scherzo_release_pedal (scherzo_t *scherzo);
 
 static void
-_judge_pitch (scherzo_t *scherzo, pitch_t pitch);
+pitch_group_remove_pitches (pitch_group_t *group);
 
 static void
-_score_challenge (scherzo_t *scherzo);
+scherzo_update_notes_and_chord (scherzo_t *scherzo);
 
 static int
 on_delete_event_quit (unused (GtkWidget *widget),
@@ -149,9 +150,7 @@ on_key_press_event (GtkWidget *widget,
 {
     scherzo_t *scherzo = user_data;
     int octave;
-    /* Initialize to keep the compiler quiet. */
-    pitch_name_t pitch_name = PITCH_NATURAL (C, 0);
-    pitch_t pitch;
+    pitch_t pitch = PITCH_NOT_A_PITCH;
 
     if (scherzo->challenge.active)
 	octave = PITCH_OCTAVE (scherzo->challenge.pitch);
@@ -173,38 +172,89 @@ on_key_press_event (GtkWidget *widget,
 	gtk_widget_queue_draw (widget);
 	return TRUE;
 	break;
-    case GDK_KEY_q:
-    case GDK_KEY_Q:
     case GDK_KEY_Escape:
 	gtk_main_quit ();
 	return FALSE;
-    case GDK_KEY_c:
-    case GDK_KEY_C:
-	pitch_name = PITCH_NAME_C;
+    /* Map a piano keyboard onto the computer keyboard with white keys
+     * along the home row, (piano C on computer A, up to next octave
+     * higher C on computer K). Black keys are in the expected
+     * positions, (C# is W, D# is E, etc.).
+     */
+    case GDK_KEY_a:
+    case GDK_KEY_A:
+	pitch = PITCH_LITERAL (C, NATURAL, octave);
+	break;
+    case GDK_KEY_s:
+    case GDK_KEY_S:
+	pitch = PITCH_LITERAL (D, NATURAL, octave);
 	break;
     case GDK_KEY_d:
     case GDK_KEY_D:
-	pitch_name = PITCH_NAME_D;
-	break;
-    case GDK_KEY_e:
-    case GDK_KEY_E:
-	pitch_name = PITCH_NAME_E;
+	pitch = PITCH_LITERAL (E, NATURAL, octave);
 	break;
     case GDK_KEY_f:
     case GDK_KEY_F:
-	pitch_name = PITCH_NAME_F;
+	pitch = PITCH_LITERAL (F, NATURAL, octave);
 	break;
     case GDK_KEY_g:
     case GDK_KEY_G:
-	pitch_name = PITCH_NAME_G;
+	pitch = PITCH_LITERAL (G, NATURAL, octave);
 	break;
-    case GDK_KEY_a:
-    case GDK_KEY_A:
-	pitch_name = PITCH_NAME_A;
+    case GDK_KEY_h:
+    case GDK_KEY_H:
+	pitch = PITCH_LITERAL (A, NATURAL, octave);
 	break;
-    case GDK_KEY_b:
-    case GDK_KEY_B:
-	pitch_name = PITCH_NAME_B;
+    case GDK_KEY_j:
+    case GDK_KEY_J:
+	pitch = PITCH_LITERAL (B, NATURAL, octave);
+	break;
+    case GDK_KEY_k:
+    case GDK_KEY_K:
+	pitch = PITCH_LITERAL (C, NATURAL, octave + 1);
+	break;
+    case GDK_KEY_l:
+    case GDK_KEY_L:
+	pitch = PITCH_LITERAL (D, NATURAL, octave + 1);
+	break;
+    case GDK_KEY_semicolon:
+    case GDK_KEY_colon:
+	pitch = PITCH_LITERAL (E, NATURAL, octave + 1);
+	break;
+    case GDK_KEY_apostrophe:
+    case GDK_KEY_quotedbl:
+	pitch = PITCH_LITERAL (F, NATURAL, octave + 1);
+	break;
+    case GDK_KEY_w:
+    case GDK_KEY_W:
+	pitch = PITCH_LITERAL (C, SHARP, octave);
+	break;
+    case GDK_KEY_e:
+    case GDK_KEY_E:
+	pitch = PITCH_LITERAL (D, SHARP, octave);
+	break;
+    case GDK_KEY_t:
+    case GDK_KEY_T:
+	pitch = PITCH_LITERAL (F, SHARP, octave);
+	break;
+    case GDK_KEY_y:
+    case GDK_KEY_Y:
+	pitch = PITCH_LITERAL (G, SHARP, octave);
+	break;
+    case GDK_KEY_u:
+    case GDK_KEY_U:
+	pitch = PITCH_LITERAL (A, SHARP, octave);
+	break;
+    case GDK_KEY_o:
+    case GDK_KEY_O:
+	pitch = PITCH_LITERAL (C, SHARP, octave + 1);
+	break;
+    case GDK_KEY_p:
+    case GDK_KEY_P:
+	pitch = PITCH_LITERAL (D, SHARP, octave + 1);
+	break;
+    case GDK_KEY_bracketright:
+    case GDK_KEY_braceright:
+	pitch = PITCH_LITERAL (F, SHARP, octave + 1);
 	break;
     case GDK_KEY_0:
     case GDK_KEY_1:
@@ -220,29 +270,23 @@ on_key_press_event (GtkWidget *widget,
     case GDK_KEY_space:
 	scherzo_press_pedal (scherzo);
 	break;
-    case GDK_KEY_Up:
-	if (scherzo->keyboard_accidental < PITCH_ACCIDENTAL_DOUBLE_SHARP)
-	    scherzo->keyboard_accidental++;
-	break;
-    case GDK_KEY_Down:
-	if (scherzo->keyboard_accidental > PITCH_ACCIDENTAL_DOUBLE_FLAT)
-	    scherzo->keyboard_accidental--;
+    case GDK_KEY_Return:
+	/* Clear all notes when Return is pressed. */
+	pitch_group_remove_pitches (&scherzo->notes_pressed);
+	pitch_group_remove_pitches (&scherzo->notes_pedaled);
+	scherzo_update_notes_and_chord (scherzo);
 	break;
     }
 
-    pitch = PITCH (pitch_name, scherzo->keyboard_accidental, octave);
-
-    if ((key->keyval >= GDK_KEY_A && key->keyval <= GDK_KEY_G) ||
-	(key->keyval >= GDK_KEY_a && key->keyval <= GDK_KEY_g))
+    if (pitch != PITCH_NOT_A_PITCH) 
     {
+	pitch = scherzo_key_spell_pitch (&scherzo->key, pitch);
+
 	scherzo_press_note (scherzo, pitch);
-	_judge_pitch (scherzo, pitch);
-	gtk_widget_queue_draw (scherzo->window);
 
 	return TRUE;
     }
 
-
     /* Allow an unhandled event to propagate to other handlers. */
     return FALSE;
 }
@@ -254,9 +298,7 @@ on_key_release_event (unused (GtkWidget *widget),
 {
     scherzo_t *scherzo = user_data;
     int octave;
-    /* Initialize to keep the compiler quiet. */
-    pitch_name_t pitch_name = PITCH_NAME_C;
-    pitch_t pitch;
+    pitch_t pitch = PITCH_NOT_A_PITCH;
 
     if (scherzo->challenge.active)
 	octave = PITCH_OCTAVE (scherzo->challenge.pitch);
@@ -264,151 +306,99 @@ on_key_release_event (unused (GtkWidget *widget),
 	octave = scherzo->keyboard_octave;
 
     switch (key->keyval) {
-    case GDK_KEY_c:
-    case GDK_KEY_C:
-	pitch_name = PITCH_NAME_C;
+    case GDK_KEY_a:
+    case GDK_KEY_A:
+	pitch = PITCH_LITERAL (C, NATURAL, octave);
+	break;
+    case GDK_KEY_s:
+    case GDK_KEY_S:
+	pitch = PITCH_LITERAL (D, NATURAL, octave);
 	break;
     case GDK_KEY_d:
     case GDK_KEY_D:
-	pitch_name = PITCH_NAME_D;
-	break;
-    case GDK_KEY_e:
-    case GDK_KEY_E:
-	pitch_name = PITCH_NAME_E;
+	pitch = PITCH_LITERAL (E, NATURAL, octave);
 	break;
     case GDK_KEY_f:
     case GDK_KEY_F:
-	pitch_name = PITCH_NAME_F;
+	pitch = PITCH_LITERAL (F, NATURAL, octave);
 	break;
     case GDK_KEY_g:
     case GDK_KEY_G:
-	pitch_name = PITCH_NAME_G;
+	pitch = PITCH_LITERAL (G, NATURAL, octave);
 	break;
-    case GDK_KEY_a:
-    case GDK_KEY_A:
-	pitch_name = PITCH_NAME_A;
+    case GDK_KEY_h:
+    case GDK_KEY_H:
+	pitch = PITCH_LITERAL (A, NATURAL, octave);
 	break;
-    case GDK_KEY_b:
-    case GDK_KEY_B:
-	pitch_name = PITCH_NAME_B;
+    case GDK_KEY_j:
+    case GDK_KEY_J:
+	pitch = PITCH_LITERAL (B, NATURAL, octave);
 	break;
-    case GDK_KEY_space:
-	scherzo_release_pedal (scherzo);
+    case GDK_KEY_k:
+    case GDK_KEY_K:
+	pitch = PITCH_LITERAL (C, NATURAL, octave + 1);
 	break;
-    }
-
-    pitch = PITCH (pitch_name, scherzo->keyboard_accidental, octave);
-
-    if ((key->keyval >= GDK_KEY_A && key->keyval <= GDK_KEY_G) ||
-	(key->keyval >= GDK_KEY_a && key->keyval <= GDK_KEY_g))
-    {
-	scherzo_release_note (scherzo, pitch);
-	_score_challenge (scherzo);
-	gtk_widget_queue_draw (scherzo->window);
-
-	return TRUE;
-    }
-
-
-    /* Allow an unhandled event to propagate to other handlers. */
-    return FALSE;
-}
-
-static unsigned char
-_pitch_to_midi (pitch_t pitch)
-{
-    int octave = PITCH_OCTAVE (pitch);
-    unsigned char midi_note = 12 * (octave + 1);
-
-    switch (PITCH_NAME (pitch)) {
-    case PITCH_NAME_C:
+    case GDK_KEY_l:
+    case GDK_KEY_L:
+	pitch = PITCH_LITERAL (D, NATURAL, octave + 1);
 	break;
-    case PITCH_NAME_D:
-	midi_note += 2;
+    case GDK_KEY_semicolon:
+    case GDK_KEY_colon:
+	pitch = PITCH_LITERAL (E, NATURAL, octave + 1);
 	break;
-    case PITCH_NAME_E:
-	midi_note += 4;
+    case GDK_KEY_apostrophe:
+    case GDK_KEY_quotedbl:
+	pitch = PITCH_LITERAL (F, NATURAL, octave + 1);
 	break;
-    case PITCH_NAME_F:
-	midi_note += 5;
+    case GDK_KEY_w:
+    case GDK_KEY_W:
+	pitch = PITCH_LITERAL (C, SHARP, octave);
 	break;
-    case PITCH_NAME_G:
-	midi_note += 7;
+    case GDK_KEY_e:
+    case GDK_KEY_E:
+	pitch = PITCH_LITERAL (D, SHARP, octave);
 	break;
-    case PITCH_NAME_A:
-	midi_note += 9;
+    case GDK_KEY_t:
+    case GDK_KEY_T:
+	pitch = PITCH_LITERAL (F, SHARP, octave);
 	break;
-    case PITCH_NAME_B:
-	midi_note += 11;
+    case GDK_KEY_y:
+    case GDK_KEY_Y:
+	pitch = PITCH_LITERAL (G, SHARP, octave);
 	break;
-    }
-
-    switch (PITCH_ACCIDENTAL (pitch)) {
-    case PITCH_ACCIDENTAL_DOUBLE_FLAT:
-	midi_note -= 2;
+    case GDK_KEY_u:
+    case GDK_KEY_U:
+	pitch = PITCH_LITERAL (A, SHARP, octave);
 	break;
-    case PITCH_ACCIDENTAL_FLAT:
-	midi_note -= 1;
+    case GDK_KEY_o:
+    case GDK_KEY_O:
+	pitch = PITCH_LITERAL (C, SHARP, octave + 1);
 	break;
-    case PITCH_ACCIDENTAL_NATURAL:
+    case GDK_KEY_p:
+    case GDK_KEY_P:
+	pitch = PITCH_LITERAL (D, SHARP, octave + 1);
 	break;
-    case PITCH_ACCIDENTAL_SHARP:
-	midi_note += 1;
+    case GDK_KEY_bracketright:
+    case GDK_KEY_braceright:
+	pitch = PITCH_LITERAL (F, SHARP, octave + 1);
 	break;
-    case PITCH_ACCIDENTAL_DOUBLE_SHARP:
-	midi_note += 2;
+    case GDK_KEY_space:
+	scherzo_release_pedal (scherzo);
 	break;
     }
 
-    return midi_note;
-}
+    if (pitch != PITCH_NOT_A_PITCH)
+    {
+	pitch = scherzo_key_spell_pitch (&scherzo->key, pitch);
 
-/* octave can optionally by NULL */
-static pitch_t
-_midi_to_pitch (unsigned char midi_note)
-{
-    int octave = octave = midi_note / 12 - 1;
+	scherzo_release_note (scherzo, pitch);
 
-    switch (midi_note % 12)
-    {
-    default:
-    case 0:
-	return PITCH_LITERAL (C, NATURAL, octave);
-	break;
-    case 1:
-	return PITCH_LITERAL (C, SHARP, octave);
-	break;
-    case 2:
-	return PITCH_LITERAL (D, NATURAL, octave);
-	break;
-    case 3:
-	return PITCH_LITERAL (D, SHARP, octave);
-	break;
-    case 4:
-	return PITCH_LITERAL (E, NATURAL, octave);
-	break;
-    case 5:
-	return PITCH_LITERAL (F, NATURAL, octave);
-	break;
-    case 6:
-	return PITCH_LITERAL (F, SHARP, octave);
-	break;
-    case 7:
-	return PITCH_LITERAL (G, NATURAL, octave);
-	break;
-    case 8:
-	return PITCH_LITERAL (G, SHARP, octave);
-	break;
-    case 9:
-	return PITCH_LITERAL (A, NATURAL, octave);
-	break;
-    case 10:
-	return PITCH_LITERAL (A, SHARP, octave);
-	break;
-    case 11:
-	return PITCH_LITERAL (B, NATURAL, octave);
-	break;
+	return TRUE;
     }
+
+
+    /* Allow an unhandled event to propagate to other handlers. */
+    return FALSE;
 }
 
 /* Return true if 'a' and 'b' sound identical, (even if spelled differently)
@@ -419,7 +409,7 @@ _midi_to_pitch (unsigned char midi_note)
 static int
 _pitches_are_enharmonic (pitch_t a, pitch_t b)
 {
-    return _pitch_to_midi (a) == _pitch_to_midi (b);
+    return pitch_to_midi (a) == pitch_to_midi (b);
 }
 
 /* Determine a chord name (if any) from the current notes pressed */
@@ -500,20 +490,6 @@ _modified_degree_to_half_steps (const modified_degree_t *degree)
     return half_steps + degree->modification;
 }
 
-/* Number of half steps from 'root' up to 'pitch' (that is, counting
- * the steps up a chromatic scale), within the same octave. */
-static int
-_pitch_from_root_in_half_steps (pitch_t pitch, pitch_t root)
-{
-    int root_midi = _pitch_to_midi (root);
-    int pitch_midi = _pitch_to_midi (pitch);
-
-    while (pitch_midi < root_midi)
-	pitch_midi += 12;
-
-    return (pitch_midi - root_midi) % 12;
-}
-
 static int
 _chord_signature_matches (analyzed_pitch_t *pitches,
 			  int num_pitches,
@@ -561,61 +537,6 @@ _chord_signature_matches (analyzed_pitch_t *pitches,
     return 1;
 }
 
-static const char *
-_pitch_str (pitch_t pitch)
-{
-    static char double_flat[] = "X𝄫";
-    static char flat[] = "X♭";
-    static char natural[] = "X";
-    static char sharp[] = "X♯";
-    static char double_sharp[] = "X𝄪";
-    char *ret;
-
-    switch (PITCH_ACCIDENTAL (pitch)) {
-    case PITCH_ACCIDENTAL_DOUBLE_FLAT:
-	ret = double_flat;
-	break;
-    case PITCH_ACCIDENTAL_FLAT:
-	ret = flat;
-	break;
-    case PITCH_ACCIDENTAL_NATURAL:
-	ret = natural;
-	break;
-    case PITCH_ACCIDENTAL_SHARP:
-	ret = sharp;
-	break;
-    case PITCH_ACCIDENTAL_DOUBLE_SHARP:
-	ret = double_sharp;
-	break;
-    }
-
-    switch (PITCH_NAME(pitch)) {
-    case PITCH_NAME_C:
-	ret[0] = 'C';
-	break;
-    case PITCH_NAME_D:
-	ret[0] = 'D';
-	break;
-    case PITCH_NAME_E:
-	ret[0] = 'E';
-	break;
-    case PITCH_NAME_F:
-	ret[0] = 'F';
-	break;
-    case PITCH_NAME_G:
-	ret[0] = 'G';
-	break;
-    case PITCH_NAME_A:
-	ret[0] = 'A';
-	break;
-    case PITCH_NAME_B:
-	ret[0] = 'B';
-	break;
-    }
-
-    return ret;
-}
-
 typedef struct chord_signature
 {
     int num_degrees;
@@ -764,108 +685,22 @@ chord_signature_t signatures[] = {
     { 6, {{1, 0}, {9, -1}, {3, -1}, {11, -1}, {5, -1}, {7, -2}}, "°" SUP "11" PUS }
 };
 
-static void
-scherzo_adjust_pitch_to_match_modified_degree (pitch_t *pitch,
-					       pitch_t root,
-					       modified_degree_t *degree)
-{
-    pitch_name_t name = PITCH_NAME (*pitch);
-    pitch_accidental_t accidental = PITCH_ACCIDENTAL (*pitch);
-    int octave = PITCH_OCTAVE (*pitch);
-    int degree_zero_based = (degree->degree - 1) % 7;
-    int degree_delta;
-
-    int note_degree_zero_based = name - PITCH_NAME (root);
-    if (note_degree_zero_based < 0)
-	note_degree_zero_based += 7;
-
-    if (note_degree_zero_based == degree_zero_based)
-	return;
-
-    degree_delta = note_degree_zero_based - degree_zero_based;
-    if (degree_delta > 3)
-	degree_delta = - (7 - degree_delta);
-    if (degree_delta < -3)
-	degree_delta = - (-7 - degree_delta);
-
-    if (abs (degree_delta) != 1) {
-	fprintf (stderr, "Internal error: Cannot adjust a note more than one degree (%d vs. %d).\n", note_degree_zero_based + 1, degree->degree);
-	exit (1);
-    }
-
-    if (degree_delta == -1) {
-	if (name == PITCH_NAME_B) {
-	    name = PITCH_NAME_C;
-	    octave++;
-	} else {
-	    name++;
-	}
-	switch (name) {
-	case PITCH_NAME_D:
-	case PITCH_NAME_E:
-	case PITCH_NAME_G:
-	case PITCH_NAME_A:
-	case PITCH_NAME_B:
-	    accidental -= 2;
-	    break;
-	case PITCH_NAME_C:
-	case PITCH_NAME_F:
-	    accidental -= 1;
-	    break;
-	}
-    }
-
-    if (degree_delta == +1) {
-	if (name == PITCH_NAME_C) {
-	    name = PITCH_NAME_B;
-	    octave--;
-	} else {
-	    name--;
-	}
-	switch (name) {
-	case PITCH_NAME_C:
-	case PITCH_NAME_D:
-	case PITCH_NAME_F:
-	case PITCH_NAME_G:
-	case PITCH_NAME_A:
-	    accidental += 2;
-	    break;
-	case PITCH_NAME_E:
-	case PITCH_NAME_B:
-	    accidental += 1;
-	}
-    }
-
-    if (accidental < 0 || accidental > PITCH_ACCIDENTAL_DOUBLE_SHARP) {
-	fprintf (stderr, "Internal error: Trying to adjust an accidental out of range (degree_delta == %d (%d - %d), new accidental == %d).\n", degree_delta, note_degree_zero_based, degree_zero_based, accidental);
-	exit (1);
-    }
-
-    *pitch = PITCH (name, accidental, octave);
-}
-
 static void
 _spell_chord_by_signature (pitch_group_t *chord,
 			   chord_signature_t *signature,
 			   pitch_t root)
 {
     int i, degree, note_half_steps, degree_half_steps;
-    int root_midi;
-
-    /* Sanitize root to eliminate things like double-flats,
-     * double-sharps, Cb, E#, etc. */
-    root_midi = _pitch_to_midi (root);
-    root = _midi_to_pitch (root_midi);
     
     for (i = 0; i < chord->num_pitches; i++) {
-	note_half_steps = _pitch_from_root_in_half_steps (chord->pitches[i],
+	note_half_steps = pitch_from_root_in_half_steps (chord->pitches[i],
 							  root);
 	for (degree = 0; degree < signature->num_degrees; degree++) {
 	    degree_half_steps = _modified_degree_to_half_steps (&signature->degrees[degree]);
 	    if (note_half_steps == degree_half_steps) {
-		scherzo_adjust_pitch_to_match_modified_degree (&chord->pitches[i],
-							       root,
-							       &signature->degrees[degree]);
+		chord->pitches[i] = pitch_spell_as_degree (chord->pitches[i],
+							   root,
+							   signature->degrees[degree].degree);
 		break;
 	    }
 	}
@@ -904,7 +739,7 @@ _analyze_chord (pitch_group_t *chord,
     for (i = 0; i < num_pitches; i++) {
 	pitch_t pitch = chord->pitches[i];
 	pitches[i].pitch = pitch;
-	pitches[i].midi_pitch = _pitch_to_midi (pitch);
+	pitches[i].midi_pitch = pitch_to_midi (pitch);
 	/* Relative pitch will be filled in after sorting. */
 	pitches[i].relative_pitch = 0;
     }
@@ -1058,22 +893,16 @@ pitch_group_remove_pitch (pitch_group_t *group, pitch_t pitch)
 }
 */
 
+/* Remove all pitches from a pitch_group_t */
 static void
-scherzo_update_notes_and_chord (scherzo_t *scherzo)
+pitch_group_remove_pitches (pitch_group_t *group)
 {
-    if (scherzo->notes_pressed.num_pitches == 0 &&
-	scherzo->notes_pedaled.num_pitches == 0)
-    {
-	score_remove_notes (scherzo->score);
-
-	score_remove_chords (scherzo->score);
-
-	gtk_widget_queue_draw (scherzo->window);
-    }
+    talloc_free (group->pitches);
+    pitch_group_init (group->ctx, group);
 }
 
 static void
-scherzo_press_note (scherzo_t *scherzo, pitch_t pitch)
+scherzo_update_notes_and_chord (scherzo_t *scherzo)
 {
     void *local = talloc_new (NULL);
     pitch_group_t *chord;
@@ -1082,16 +911,6 @@ scherzo_press_note (scherzo_t *scherzo, pitch_t pitch)
     pitch_t *root;
     int i;
 
-    /* Do nothing if this note is already pressed. */
-    for (i = 0; i < scherzo->notes_pressed.num_pitches; i++)
-	if (scherzo->notes_pressed.pitches[i] == pitch)
-	    return;
-
-    pitch_group_add_pitch (&scherzo->notes_pressed, pitch);
-
-    if (scherzo->pedal_pressed)
-	pitch_group_add_pitch (&scherzo->notes_pedaled, pitch);
-
     /* Remove all notes/chords from score, then add current notes. */
     score_remove_notes (scherzo->score);
     score_remove_chords (scherzo->score);
@@ -1107,7 +926,17 @@ scherzo_press_note (scherzo_t *scherzo, pitch_t pitch)
 	/* Don't print root pitch for octaves and inversions,
 	 * (since a pitch name alone looks like a major triad) */
 	if (signature->num_degrees < 3) {
+	    /* In fact, don't print anything for octaves and
+	     * inversions for now. It leads to a bit of flashing when
+	     * playing chords.
+	     *
+	     * FIXME: What I'd like to have here is a small timeout,
+	     * such that names only appear once an interval has been
+	     * held for at least 100 ms or so. With that, it would be
+	     * nice to display the interval names once again.
+	     *
 	    chord_name = talloc_strdup (local, signature->name);
+	    */
 	} else {
 	    _spell_chord_by_signature (&scherzo->notes_pressed,
 				       signature, *root);
@@ -1115,7 +944,7 @@ scherzo_press_note (scherzo_t *scherzo, pitch_t pitch)
 				       signature, *root);
 
 	    chord_name = talloc_asprintf (local, "%s%s",
-					  _pitch_str (*root),
+					  pitch_string (*root),
 					  signature->name);
 	}
     } else if (chord->num_pitches > 2) {
@@ -1137,32 +966,88 @@ scherzo_press_note (scherzo_t *scherzo, pitch_t pitch)
 			SCORE_DURATION_WHOLE);
     }
 
+    gtk_widget_queue_draw (scherzo->window);
+
     talloc_free (local);
 }
 
+static void
+scherzo_set_key (scherzo_t *scherzo, pitch_t pitch)
+{
+    scherzo_key_init (&scherzo->key, pitch);
+    score_set_key (scherzo->score, pitch);
+}
+
+static bool
+pitches_are_diatonic_scale (pitch_t *pitches, int num_pitches)
+{
+    int diatonic_half_steps[7] = {
+	0, 2, 4, 5, 7, 9, 11
+    };
+    int half_steps;
+    pitch_t root;
+    int i;
+
+    if (num_pitches < 7)
+	return 0;
+
+    root = pitches[0];
+
+    for (i = 0; i < 7; i++) {
+	half_steps = pitch_from_root_in_half_steps (pitches[i], root);
+	if (half_steps != diatonic_half_steps[i])
+	    return false;
+    }
+
+    return true;
+}
+
+static void
+scherzo_press_note (scherzo_t *scherzo, pitch_t pitch)
+{
+    int i;
+
+#define NUM_RECENT_PITCHES 7
+    static pitch_t recent_pitches[NUM_RECENT_PITCHES];
+
+    memmove (recent_pitches, recent_pitches + 1,
+	     (NUM_RECENT_PITCHES - 1) * sizeof (pitch_t));
+    recent_pitches[NUM_RECENT_PITCHES - 1] = pitch;
+
+    if (pitches_are_diatonic_scale (recent_pitches, NUM_RECENT_PITCHES))
+	scherzo_set_key (scherzo, recent_pitches[0]);
+
+    /* Do nothing if this note is already pressed. */
+    for (i = 0; i < scherzo->notes_pressed.num_pitches; i++)
+	if (scherzo->notes_pressed.pitches[i] == pitch)
+	    return;
+
+    pitch_group_add_pitch (&scherzo->notes_pressed, pitch);
+
+    if (scherzo->pedal_pressed)
+	pitch_group_add_pitch (&scherzo->notes_pedaled, pitch);
+
+    scherzo_update_notes_and_chord (scherzo);
+}
+
 static void
 scherzo_release_note (scherzo_t *scherzo, pitch_t pitch)
 {
     pitch_group_remove_pitch_enharmonic (&scherzo->notes_pressed, pitch);
 
-    if (scherzo->notes_pressed.num_pitches == 0)
-	scherzo_update_notes_and_chord (scherzo);
+    scherzo_update_notes_and_chord (scherzo);
 }
 
-static pitch_t
+static void
 scherzo_press_note_midi (scherzo_t *scherzo, unsigned char midi_note)
 {
-    pitch_t pitch = _midi_to_pitch (midi_note);
-
-    scherzo_press_note (scherzo, pitch);
-
-    return pitch;
+    scherzo_press_note (scherzo, pitch_from_midi (midi_note));
 }
 
 static void
 scherzo_release_note_midi (scherzo_t *scherzo, unsigned char midi_note)
 {
-    scherzo_release_note (scherzo, _midi_to_pitch (midi_note));
+    scherzo_release_note (scherzo, pitch_from_midi (midi_note));
 }
 
 static void
@@ -1197,6 +1082,7 @@ scherzo_release_pedal (scherzo_t *scherzo)
     scherzo_update_notes_and_chord (scherzo);
 }
 
+#if 0
 static void
 _select_challenge (scherzo_t *scherzo)
 {
@@ -1305,6 +1191,7 @@ _score_challenge (scherzo_t *scherzo)
 
     _select_challenge (scherzo);
 }
+#endif
 
 static int
 on_midi_input (unused (GIOChannel *channel),
@@ -1315,8 +1202,6 @@ on_midi_input (unused (GIOChannel *channel),
     scherzo_t *scherzo = user_data;
     ssize_t remaining;
     snd_seq_event_t event;
-    pitch_t pitch;
-    int need_redraw = FALSE;
 
     remaining = read (scherzo->midi_fd, buf, MIDI_BUF_SIZE);
 
@@ -1335,14 +1220,10 @@ on_midi_input (unused (GIOChannel *channel),
 	    /* Incomplete event. Nothing to do. */
 	    break;
 	case SND_SEQ_EVENT_NOTEON:
-	    pitch = scherzo_press_note_midi (scherzo, event.data.note.note);
-	    _judge_pitch (scherzo, pitch);
-	    need_redraw = TRUE;
+	    scherzo_press_note_midi (scherzo, event.data.note.note);
 	    break;
 	case SND_SEQ_EVENT_NOTEOFF:
 	    scherzo_release_note_midi (scherzo, event.data.note.note);
-	    _score_challenge (scherzo);
-	    need_redraw = TRUE;
 	    break;
 	case SND_SEQ_EVENT_CLOCK:
 	    /* Ignore for now as my piano sends a constant stream of these. */
@@ -1370,9 +1251,6 @@ on_midi_input (unused (GIOChannel *channel),
 	}
     }
 
-    if (need_redraw)
-	gtk_widget_queue_draw (scherzo->window);
-
     /* Return TRUE to continue to get called in the future. */
     return TRUE;
 }
@@ -1400,15 +1278,17 @@ main (int argc, char *argv[])
 
     scherzo.chord = NULL;
 
-    /* Default to octave 4 and natural for computer keyboard keypresses. */
+    /* Default to octave 4 for computer keyboard keypresses. */
     scherzo.keyboard_octave = 4;
-    scherzo.keyboard_accidental = PITCH_ACCIDENTAL_NATURAL;
 
     pitch_group_init (scherzo.ctx, &scherzo.notes_pressed);
     pitch_group_init (scherzo.ctx, &scherzo.notes_pedaled);
 
     scherzo.pedal_pressed = 0;
 
+    /* Default to key of C Major, naturally. */
+    scherzo_set_key (&scherzo, PITCH_CLASS_LITERAL (C, NATURAL));
+
     mnemon_init (&scherzo.mnemon);
     /* XXX: Should create a default file if one cannot be loaded. */
     mnemon_load_category (&scherzo.mnemon, "scherzo-notes");