diff --git a/games/keen/Makefile b/games/keen/Makefile
index 8c134e9f..fd46c660 100644
--- a/games/keen/Makefile
+++ b/games/keen/Makefile
@@ -51,6 +51,7 @@ KEEN_MARS:	keen_mars.o
 	ld65 -o KEEN_MARS keen_mars.o -C ../../linker_scripts/apple2_2000.inc
 
 keen_mars.o:	keen_mars.s zp.inc hardware.inc \
+	sound_effects.s speaker_tone.s \
 	maps/mars_map.gr.zx02 graphics/parts.gr.zx02
 	ca65 -o keen_mars.o keen_mars.s -l keen_mars.lst
 
diff --git a/games/keen/keen_mars.s b/games/keen/keen_mars.s
index ae2670f6..7719d6cb 100644
--- a/games/keen/keen_mars.s
+++ b/games/keen/keen_mars.s
@@ -129,6 +129,10 @@ do_keen_loop:
 done_with_keen:
 	bit	KEYRESET	; clear keypress
 
+	; sound effect
+
+	jsr	entry_music
+;	jsr	exit_music
 
         lda     #LOAD_KEEN1
         sta     WHICH_LOAD
diff --git a/games/keen/loader.s b/games/keen/loader.s
index bf56fb1b..ff9bbe63 100644
--- a/games/keen/loader.s
+++ b/games/keen/loader.s
@@ -705,7 +705,6 @@ sectbl:	.byte $00,$0d,$0b,$09,$07,$05,$03,$01,$0e,$0c,$0a,$08,$06,$04,$02,$0f
 
 					;dataend         = filbuf+4
 
-	.include	"init_vars.s"
 
 loader_end:
 
diff --git a/games/keen/sound_effects.s b/games/keen/sound_effects.s
index fb1c0acd..6ea9ba12 100644
--- a/games/keen/sound_effects.s
+++ b/games/keen/sound_effects.s
@@ -1,3 +1,96 @@
+	;=====================
+	; entry music
+entry_music:
+	lda	SOUND_STATUS
+	bmi	done_entry_music
+
+	; music from _mr_m_ on Commander Keen Forum, Jun 5 2009
+	; 4* D5 32
+	; 4* A4 32
+	; D5 A4 D5 G5 (all 8th)
+
+	lda	#0
+	sta	MUSIC_PTR
+entry_music_loop:
+	ldx	MUSIC_PTR
+	lda	entry_music_freq,X
+	beq	done_entry_music
+	sta	speaker_frequency
+	lda	entry_music_len,X
+	sta	speaker_duration
+	jsr	speaker_tone
+
+	lda	#100
+	jsr	WAIT	; FIXME: won't work if language card active
+
+	inc	MUSIC_PTR
+	jmp	entry_music_loop
+
+done_entry_music:
+	rts
+
+
+entry_music_freq:
+	.byte NOTE_D5,NOTE_D5,NOTE_D5,NOTE_D5
+	.byte NOTE_A4,NOTE_A4,NOTE_A4,NOTE_A4
+	.byte NOTE_D5,NOTE_A4,NOTE_D5,NOTE_G5
+	.byte 0
+
+entry_music_len:
+	.byte 16,16,16,16
+	.byte 16,16,16,16
+	.byte 64,64,64,64
+
+
+
+
+	;=====================
+	; exit music
+exit_music:
+	lda	SOUND_STATUS
+	bmi	done_exit_music
+
+	; all 16 notes
+	; F#4 A#4 C5 D5 D#5 F5
+	; G4 G4 G4
+
+	lda	#0
+	sta	MUSIC_PTR
+exit_music_loop:
+	ldx	MUSIC_PTR
+	lda	exit_music_freq,X
+	beq	done_exit_music
+	sta	speaker_frequency
+	lda	exit_music_len,X
+	sta	speaker_duration
+	jsr	speaker_tone
+
+	lda	#100
+	jsr	WAIT	; FIXME: won't work if language card active
+
+	inc	MUSIC_PTR
+	jmp	exit_music_loop
+
+done_exit_music:
+	rts
+
+	; all 16 notes
+	; F#4 A#4 C5 D5 D#5 F5
+	; G4 G4 G4
+
+exit_music_freq:
+	.byte NOTE_FSHARP4,NOTE_ASHARP4,NOTE_C5,NOTE_D5
+	.byte NOTE_DSHARP5,NOTE_F5,NOTE_G4,NOTE_G4
+	.byte NOTE_G4
+	.byte 0
+
+exit_music_len:
+	.byte 48,48,48,48
+	.byte 48,48,48,48
+	.byte 48
+
+
+
 	;======================
 	; noise when jump
 jump_noise:
diff --git a/games/keen/zp.inc b/games/keen/zp.inc
index 4cd1a3b4..5966c174 100644
--- a/games/keen/zp.inc
+++ b/games/keen/zp.inc
@@ -186,7 +186,7 @@ SAMPLE_H        = $F3
 
 
 
-
+MUSIC_PTR	=	$F7
 LEADING_ZERO	=	$F8
 TEMP_STATUS	=	$F9
 TEMP		=	$FA