diff --git a/hooks.asm b/hooks.asm
index 149352d..7613817 100755
--- a/hooks.asm
+++ b/hooks.asm
@@ -1482,7 +1482,7 @@ org $09F2A7 ; <- 8F27C27E - module_death.asm:56 (STA $7EC227)
 JSL.l StoreMusicOnDeath
 
 org $0CC100 ; <- A511 C904 - Bank0C.asm:07 (LDA $11 : CMP.b #$04)
-JSL.l startup_wait
+;JSL.l startup_wait
 
 org $0EE6EC ; <- E220 A922 - Bank0E.asm:2892 (SEP #$20 : LDA.b #$22 : STA $012C)
 JSL.l ending_wait
diff --git a/msu.asm b/msu.asm
index a043ddd..98eb812 100644
--- a/msu.asm
+++ b/msu.asm
@@ -383,18 +383,6 @@ StoreMusicOnDeath:
 msu_init:
     PHP
 
-    STZ $4200
-
-    LDA.b #$FF : STA $2140
-
-    LDA.b #SPCEngineNewCode     : STA.b $00
-    LDA.b #SPCEngineNewCode>>8  : STA.b $01
-    LDA.b #SPCEngineNewCode>>16
-
-    JSL Sound_LoadLightWorldSongBank_do_load
-
-    LDA.b #$81 : STA $4200
-
     LDA NoBGM : BNE .done
 
     REP #$20
diff --git a/music.asm b/music.asm
index 9269a90..72a1d2f 100644
--- a/music.asm
+++ b/music.asm
@@ -279,22 +279,3 @@ Overworld_MosaicDarkWorldChecks:
 .done
     RTL
 ;--------------------------------------------------------------------------------
-
-;--------------------------------------------------------------------------------
-!SPCFreeSpace = $0700
-
-SPCEngineNewCode:
-dw .end-.start
-dw !SPCFreeSpace
-.start
-incsrc spc.asm
-.end
-
-dw $0004
-dw $0A73            ; $0A73: CMP A,#$F0
-db $5F              ; JMP SPCFreeSpace
-dw !SPCFreeSpace
-db $00              ; NOP
-
-dw $0000, $0000
-;--------------------------------------------------------------------------------
\ No newline at end of file
diff --git a/spc.asm b/spc.asm
index 58865ed..1a14d62 100644
--- a/spc.asm
+++ b/spc.asm
@@ -1,47 +1,106 @@
-;=======================================
-; SPC engine changes
-;
-; Free space at $040F-07FF (probably)
-;
-; If we ever switch to ASAR we can rewrite
-; this as actual SPC asm instead of this
-; db jank.
+// Build with bass v15
+// This code apparently triggers a pathalogical edge case
+// which breaks forward labels, necessitating db-style branches
+// but the code is really only for documentation anyway, we're
+// using a compiled .bps patch for actual patch generation.
 
-; seek($0700)
-db $68, $F0         ; CMP A,#$F0            ; the thing we overwrote
-db $D0, $03         ; BNE +
-db $5F, $81, $0A    ;   JMP SilenceSong     ; ($0A81)
-db $68, $FA         ; + : CMP A,#$FA        ; new mute command $FA
-db $D0, $1C         ; BNE +
-db $C4, $F4         ;   MOV $F4,A
-db $E8, $00         ;   MOV A,#$00
-db $C5, $4A, $0A    ;   MOV $0A4A,A         ; $0A49: MOV A,#$70 -> MOV A,#$00
-db $C5, $F3, $0A    ;   MOV $0AF3,A         ; $0AF2: MOV $059,#$C0 -> MOV $059,#$00
-db $C5, $32, $0C    ;   MOV $0C32,A         ; $0C32: MOVW $058,YA -> NOP #2
-db $C5, $33, $0C    ;   MOV $0C33,A
-db $E8, $C4         ;   MOV A,#$C4          ; $0D19: MOVW $058,YA -> MOV $058,A
-db $C5, $19, $0D    ;   MOV $0D19,A
-db $E8, $58         ;   MOV A,#$58
-db $C5, $1A, $0D    ;   MOV $0D1A,A
-db $2F, $23         ;   BRA ++
-db $68, $FB         ; + : CMP A,#$FB        ; new unmute command $FB
-db $F0, $03         ; BEQ +
-db $5F, $9D, $0A    ;   JMP NewSongInput    ; ($0A9D)
-db $C4, $F4         ; + :  MOV $F4,A
-db $E8, $70         ; MOV A,#$70
-db $C5, $4A, $0A    ; MOV $0A4A,A           ; $0A49: MOV A,#$70
-db $E8, $C0         ; MOV A,#$C0
-db $C5, $F3, $0A    ; MOV $0AF3,A           ; $0AF2: MOV $059,#$C0
-db $E8, $DA         ; MOV A,#$DA
-db $C5, $32, $0C    ; MOV $0C32,A           ; $0C32: MOVW $058,YA
-db $C5, $19, $0D    ; MOV $0D19,A           ; $0D19: MOVW $058,YA
-db $E8, $58         ; MOV A,#$58
-db $C5, $33, $0C    ; MOV $0C33,A
-db $C5, $1A, $0D    ; MOV $0D1A,A
-db $3F, $81, $0A    ; ++ : CALL SilenceSong ; ($0A81)
-db $E4, $F4         ; - : MOV A,$F4
-db $D0, $FC         ;       BNE -
-db $64, $F4         ;       CMP A,$F4
-db $D0, $F8         ;       BNE -
-db $FA, $00, $F4    ; MOV $F4,#$00
-db $6F              ; RET
+architecture wdc65816
+
+macro rom_seek(variable address) {
+    origin ((address & $7F0000) >> 1) | (address & $7FFF)
+    base address
+}
+
+rom_seek($400000)   // Pad ROM to 0x200000
+
+rom_seek($008901)
+lda.b #(SPC.IntroSongBank & 0xFF); sta $00
+lda.b #((SPC.IntroSongBank >> 8) & 0xFF); sta $01
+lda.b #((SPC.IntroSongBank >> 16) & 0xFF); sta $02
+
+rom_seek($348000)   // Seek to ROM offset 0x1A0000
+
+architecture spc700
+
+namespace SPC {
+constant ENGINE_ENTRYPOINT = $0800
+constant NEW_CODE_LENGTH = (EngineStart - NewCodeSection)
+constant CODE_START = (ENGINE_ENTRYPOINT - NEW_CODE_LENGTH)
+
+macro spc_seek(variable address) {
+    origin (address & $FFFF) + (((START & $7F0000) >> 1) | (START & $7FFF)) - CODE_START
+    base address
+}
+
+// Insert the original SPC transfer blocks up to the main engine code
+insert IntroSongBank, "alttp.sfc", 0x0C8000, 0x7BCA
+dw NEW_CODE_LENGTH + $0F9E  // New code is prepended to the original upload
+dw CODE_START               // of length $0F9E to destination $0800
+
+
+START:
+spc_seek(CODE_START)
+if pc() < $0700 {
+    error "SPC code out of bounds (PC < $0700)"
+}
+
+// Any new code goes here.  DON'T DELETE THIS LABEL
+// Labels not forward-declared (e.g. '+/++') don't work here
+NewCodeSection:
+
+SpecialCommand_Mute:
+cmp #$F0                    // The thing we overwrote
+// bne +
+db $D0, $03
+  jmp $0A81                 // SilenceSong
++; cmp #$FA                 // New mute command $FA
+// bne +
+db $D0, $1C
+  sta $F4
+  lda #$00
+  sta $0A4A                 // $0A49: lda #$70 -> lda #$00
+  sta $0AF3                 // $0AF2: MOV $059,#$C0 -> MOV $059,#$00
+  sta $0C32                 // $0C32: MOVW $058,YA -> NOP #2
+  sta $0C33
+  lda #$C4                  // $0D19: MOVW $058,YA -> lda $058
+  sta $0D19
+  lda #$58
+  sta $0D1A
+  // bra ++
+  db $2F, $23
++; cmp #$FB                 // New unmute command $FB
+// beq +
+db $F0, $03
+  jmp $0A9D                 // NewSongInput
++;  sta $F4
+lda #$70
+sta $0A4A                   // $0A49: lda #$70
+lda #$C0
+sta $0AF3                   // $0AF2: MOV $059,#$C0
+lda #$DA
+sta $0C32                   // $0C32: MOVW $058,YA
+sta $0D19                   // $0D19: MOVW $058,YA
+lda #$58
+sta $0C33
+sta $0D1A
++; jsr $0A81                // SilenceSong
+-; lda $F4
+      bne -
+      cmp $F4
+      bne -
+str $F4=$00                 // ACK the CPU
+rts
+
+EngineStart:
+// Upload the main engine, along with the rest of the original transfer block
+insert "alttp.sfc", 0x0CFBCE, 0x57B2
+
+// Hook to check for new special mute commands FA, FB
+spc_seek($0A73)             // $0A73: CMP A,#$F0
+jmp SpecialCommand_Mute
+nop
+
+rom_seek($0C8000)
+fill 0xD380
+
+}   // namespace SPC
\ No newline at end of file
diff --git a/tables.asm b/tables.asm
index a0b6c59..0f8dfd2 100644
--- a/tables.asm
+++ b/tables.asm
@@ -1634,48 +1634,6 @@ db $FF,$FF,$FF,$FF,$FF,$FF,$FF,$FF
 
 ;================================================================================
 org $30D800 ; PC 0x185800 - 0x18591F
-SPCMutePayload:
-dw $0001	; Transfer size
-dw $0A4A    ; Transfer destination
-db $00      ; mov a,#$70 -> mov a,#$00
-
-dw $0001    ; Transfer size
-dw $0AF3    ; Transfer destination
-db $00      ; mov $059,#$c0 -> mov $059,#$00
-
-dw $0002    ; Transfer size
-dw $0C32    ; Transfer destination
-db $00, $00 ; movw $058,ya -> nop #2
-
-dw $0001    ; Transfer size
-dw $0D19    ; Transfer destination
-db $34      ; movw $058,ya -> mov $058,a
-
-dw $0000    ; Transfer size (end of transfer)
-dw $FFFF    ; Dummy destination
-db $FF, $FF, $FF, $FF, $FF, $FF, $FF	; Padding
-
-SPCUnmutePayload:
-dw $0001	; Transfer size
-dw $0A4A    ; Transfer destination
-db $70      ; mov a,#$70
-
-dw $0001    ; Transfer size
-dw $0AF3    ; Transfer destination
-db $C0      ; mov $059,#$c0
-
-dw $0002    ; Transfer size
-dw $0C32    ; Transfer destination
-db $da, $58 ; movw $058,ya
-
-dw $0001    ; Transfer size
-dw $0D19    ; Transfer destination
-db $34      ; movw $058,ya
-
-dw $0000    ; Transfer size (end of transfer)
-dw $FFFF    ; Dummy destination
-db $FF, $FF, $FF, $FF, $FF, $FF, $FF	; Padding
-
 MSUTrackList:
 db $01,$03,$03,$03,$03,$03,$03,$01
 db $03,$01,$03,$03,$03,$03,$03,$03