diff --git a/sid.4th b/sid.4th
index 146976f..1000092 100644
--- a/sid.4th
+++ b/sid.4th
@@ -6,21 +6,22 @@
   2DUP 127 AND 84 PC2!
   128 OR 84 PC2! ;
 
+\ Voice control register flags
+: SID:CTL:GATE  1 ;
+: SID:CTL:SYNC3 2 ;
+: SID:CTL:RING3 4 ;
+: SID:CTL:TEST  8 ;
+: SID:CTL:TRI   16 ;
+: SID:CTL:SAW   32 ;
+: SID:CTL:PWM   64 ;
+: SID:CTL:NOISE 128 ;
+
 \ Voice 1
 \ Reg 0,1 - frequency voice 1
 : SID0/1:FREQ! DUP 255 AND 0 SID! >< 255 AND 1 SID! ;
 \ Reg 2,3 - pulse wave duty cycle voice 2
 : SID2/3:PWM! DUP 255 AND 2 SID! >< 15 AND 3 SID! ;
 \ Reg 4 - control register voice 1
-: SID4:GATEOFF 0 ;
-: SID4:GATEON 1 ;
-: SID4:SYNC3 2 OR ;
-: SID4:RING3 4 OR ;
-: SID4:TEST 8 OR ;
-: SID4:TRI 16 OR ;
-: SID4:SAW 32 OR ;
-: SID4:PWM 64 OR ;
-: SID4:NOISE 128 OR ;
 : SID4! 4 SID! ;
 \ Reg 5 - attack duration / decay duration voice 1
 : SID5:ATK/DEC! 15 AND SWAP 4 LSHIFT OR 5 SID! ;
@@ -33,15 +34,6 @@
 \ Reg 9,10 - pulse wave duty cycle voice 2
 : SID9/10:PWM! DUP 255 AND 9 SID! >< 255 AND 10 SID! ;
 \ Reg 10 - control register voice 2
-: SID11:GATEOFF 0 ;
-: SID11:GATEON 1 ;
-: SID11:SYNC3 2 OR ;
-: SID11:RING3 4 OR ;
-: SID11:TEST 8 OR ;
-: SID11:TRI 16 OR ;
-: SID11:SAW 32 OR ;
-: SID11:PULSE 64 OR ;
-: SID11:NOISE 128 OR ;
 : SID11! 11 SID! ;
 \ Reg 12 - attack duration / decay duration voice 2
 : SID12:ATK/DEC! 15 AND SWAP 4 LSHIFT OR 12 SID! ;
@@ -54,15 +46,6 @@
 \ Reg 16,17 - pulse wave duty cycle voice 3
 : SID16/17:PWM! DUP 255 AND 16 SID! >< 255 AND 17 SID! ;
 \ Reg 18 - control register voice 18
-: SID18:GATEOFF 0 ;
-: SID18:GATEON 1 ;
-: SID18:SYNC3 2 OR ;
-: SID18:RING3 4 OR ;
-: SID18:TEST 8 OR ;
-: SID18:TRI 16 OR ;
-: SID18:SAW 32 OR ;
-: SID18:PWM 64 OR ;
-: SID18:NOISE 128 OR ;
 : SID18! 18 SID! ;
 \ Reg 19 - attack duration / decay duration voice 3
 : SID19:ATK/DEC! 15 AND SWAP 4 LSHIFT OR 19 SID! ;
@@ -89,42 +72,74 @@
 
 \ SID:RST   -- Put SID chip in known state
 : SID:RST
-   20000 SID0/1:FREQ! SID4:GATEOFF SID4! 4 2 SID5:ATK/DEC! 15 9 SID6:SUS/REL! 2048 SID2/3:PWM!
-   20000 SID7/8:FREQ! SID11:GATEOFF SID11! 4 2 SID12:ATK/DEC! 10 9 SID13:SUS/REL! 2048 SID9/10:PWM!
-   20000 SID14/15:FREQ! SID18:GATEOFF SID18! 4 2 SID19:ATK/DEC! 10 9 SID20:SUS/REL! 2048 SID16/17:PWM!
+   4389 SID0/1:FREQ!   0 SID4!  4 2 SID5:ATK/DEC!  10 9 SID6:SUS/REL!  2048 SID2/3:PWM!
+   4389 SID7/8:FREQ!   0 SID11! 4 2 SID12:ATK/DEC! 10 9 SID13:SUS/REL! 2048 SID9/10:PWM!
+   4389 SID14/15:FREQ! 0 SID18! 4 2 SID19:ATK/DEC! 10 9 SID20:SUS/REL! 2048 SID16/17:PWM!
    1024 SID21/22:CUT! 10 SID23:RES SID23!
    15 SID24:VOL SID24! ;
 
+\ Frequency table:
+: SID:NOTE:C4  4389 ;
+: SID:NOTE:C4# 4650 ;
+: SID:NOTE:D4  4927 ;
+: SID:NOTE:D4# 5220 ;
+: SID:NOTE:E4  5530 ;
+: SID:NOTE:F4  5859 ;
+: SID:NOTE:F4# 6207 ;
+: SID:NOTE:G4  6577 ;
+: SID:NOTE:G4# 6968 ;
+: SID:NOTE:A4  7382 ;
+: SID:NOTE:A4# 7821 ;
+: SID:NOTE:B4  8286 ;
+\ Octave shifts
+: SID:OCT:UP 2* ;
+: SID:OCT:DOWN 2/ ;
+
+\ Voice contorl registers
+VARIABLE SID:V1:CTL
+: SID:V1:CTL! SID:V1:CTL ! ;
+: SID:V1:NOTE:ON SID0/1:FREQ! SID:V1:CTL @ SID:CTL:GATE OR SID4! ;
+: SID:V1:NOTE:OFF SID:V1:CTL @ SID:CTL:GATE INVERT AND SID4! ;
+
+VARIABLE SID:V2:CTL
+: SID:V2:CTL! SID:V2:CTL ! ;
+: SID:V2:NOTE:ON SID7/8:FREQ! SID:V2:CTL @ SID:CTL:GATE OR SID11! ;
+: SID:V2:NOTE:OFF SID:V2:CTL @ SID:CTL:GATE INVERT AND SID11! ;
+
+VARIABLE SID:V3:CTL
+: SID:V3:CTL! SID:V3:CTL ! ;
+: SID:V3:NOTE:ON SID14/15:FREQ! SID:V3:CTL @ SID:CTL:GATE OR SID18! ;
+: SID:V3:NOTE:OFF SID:V3:CTL @ SID:CTL:GATE INVERT AND SID18! ;
+
 : STEP 100 0 DO LOOP ;
 : DELAY 10000 0 DO LOOP ;
-: SID:TEST:SIREN
-   SID4:GATEON  SID4:TRI SID4!
-   10 0 DO 255 0 DO I 1 SID! LOOP LOOP
-   SID4:GATEOFF SID4:TRI SID4! ;
 
-: SIDV1:TEST:NOTE
-   SID4:GATEON  SID4:TRI SID4!
+: SID:V1:TEST:NOTE
+   SID:CTL:TRI SID:V1:CTL!
+   SID:NOTE:C4 SID:V1:NOTE:ON
    DELAY DELAY
-   SID4:GATEOFF SID4:TRI SID4! ;
-: SIDV2:TEST:NOTE
-   SID11:GATEON  SID11:SAW SID11!
+   SID:V1:NOTE:OFF
+: SID:V2:TEST:NOTE
+   SID:CTL:SAW SID:V2:CTL!
+   SID:NOTE:D4 SID:V2:NOTE:ON
    DELAY DELAY
-   SID11:GATEOFF SID11:SAW SID11! ;
-: SIDV3:TEST:NOTE
-   SID18:GATEON  SID18:PWM SID18!
+   SID:V2:NOTE:OFF
+: SID:V3:TEST:NOTE
+   SID:CTL:PWM SID:V3:CTL!
+   SID:NOTE:E4 SID:V3:NOTE:ON
    DELAY DELAY
-   SID18:GATEOFF SID18:PWM SID18! ;
+   SID:V3:NOTE:OFF
 
 : SID:TEST:MELODY
-   SIDV1:TEST:NOTE
-   SIDV2:TEST:NOTE
-   SIDV3:TEST:NOTE ;
+   SID:V1:TEST:NOTE
+   SID:V2:TEST:NOTE
+   SID:V3:TEST:NOTE ;
 
 : SID:TEST:FILTER
    10 SID23:RES SID23:V1 SID23:V2 SID23:V3 SID23:EXT SID23!
-   SID18:GATEON  SID18:PWM SID18!
+   SID:CTL:PWM SID:V3:CTL! SID:NOTE:D4 SID:V3:NOTE:ON
    2047 0 DO I SID21/22:CUT! 1 +LOOP
-   SID18:GATEOFF SID18:PWM SID18! ;
+   SID:V3:NOTE:OFF ;
 
 SID:RST