Music Hacking

From Sonic Retro

Music Hacking: Pointer and Header Format | Voice and Note Editing | DAC Samples, Coordination Flags, Game Specifics, and Real-Time Music Editing | Other Games and Data Locations | Tricks of the Trade

Original Credits

Guide originally created by Tweaker on May 25 2005.

Thanks to:


You must have at least basic hex knowledge. If you have no idea what hex is, then I suggest you steer clear of this guide and figure things out first. It's also recommended that you read and save a copy of the YM2612 technical documentation and maybe the PSG documentation so that you can more easily understand how the voices and coordination flags work.

Update history

  • March 29 2005: Initial release.
  • April 22 2005: Updated Chaotix info. Also added explanation on Sonic 2 Final pointer format and corrected a few bits of incorrect info. Turns out you CAN use 6 FM channels and the DAC at the same time, thanks to the music engine. Can't say it works perfectly though. :P.
  • May 24 2005: Updated with even more Sonic 2 final info. Also added music pointer locations for Ristar and Michael Jackson's Moonwalker.
  • September ?? 2005: Fucking huge update. Massive amounts of new info, mainly concerning DAC samples. All the DAC sample definitions for Sonic 3 are now available, leaving many possibilities in the field. Also, I specified the DAC samples in Sonic 1 and 2 more, so Sonic QX users can be more precise with custom imports. Also, the purpose of two more coordination flags has been found out that have to do with PSG. Then, there are the small changes. A bit of proofreading, clarification... etc. I know I promised realtime music editing this update... Sorry I couldn't get it. It's my next priority, promise. =P

Some of these random things:

  1. Added some new locations. Found a new pointer set in Sonic 3 and found the sound effect pointers as well. Can't find out what the SFX add to yet though.
  2. Got into specifics with the Sonic 2 Final pointer list. And yes, it's in the right order. :P
  3. Added "$" signs to most ROM addresses as it's more proper. Meh, nitpicky shit. =P
  4. I wrote a tutorial on porting music from one game to another. I know people have been wanting this, so here you go. ;)

  • September 2 2006: Wow, it's been over a year since the last update! Has it really been that long? o_O

Anyway, I finally got the realtime music editing section done. Savestate locations and Z80 RAM equivalents are listed, with explanations on how to tinker with music, even while it’s still playing. Also added locations for a shitload of games, mostly from my notes. I also added more to the music porting section. And once again, various corrections and such... I can't be arsed to keep track of what I change anymore, so bleh. =P

  • August 22 2011: updated by kram1024, flamewing and others with all the new info discovered recently about smps by flamewing's most recent disasm of the s&k driver.
  • August 23 2011: added missing s3/s&k Dac Sample $8E (Low Metal Hit)


Sonic Community Hacking Guide
SonED2 Manual | Subroutine Equivalency List
Sonic the Hedgehog (16-bit) | Sonic the Hedgehog (8-bit) | Sonic CD (prototype 510) | Sonic CD | Sonic CD (PC) | Sonic CD (2011) | Sonic 2 (Simon Wai prototype) | Sonic 2 (16-bit) | Sonic 2 (Master System) | Sonic 3 | Sonic 3 & Knuckles | Chaotix | Sonic Jam | Sonic Jam 6 | Sonic Adventure | Sonic Adventure DX: Director's Cut | Sonic Adventure DX: PC | Sonic Adventure (2010) | Sonic Adventure 2 | Sonic Adventure 2: Battle | Sonic Adventure 2 (PC) | Sonic Heroes | Sonic Riders | Sonic the Hedgehog (2006) | Sonic & Sega All-Stars Racing | Sonic Unleashed (Xbox 360/PS3) | Sonic Colours | Sonic Generations | Sonic Forces
Technical information
Sonic Eraser | Sonic 2 (Nick Arcade prototype) | Sonic CD (prototype; 1992-12-04) | Dr. Robotnik's Mean Bean Machine | Sonic Triple Trouble | Tails Adventures | Sonic Crackers | Sonic 3D: Flickies' Island | Sonic & Knuckles Collection | Sonic R | Sonic Shuffle | Sonic Advance | Sonic Advance 3 | Sonic Battle | Shadow the Hedgehog | Sonic Rush | Sonic Classic Collection | Sonic Free Riders | Sonic Lost World
Legacy Guides
The Nemesis Hacking Guides The Esrael Hacking Guides
ROM: Sonic 1 | Sonic 2 | Sonic 2 Beta | Sonic 3

Savestate: Sonic 1 | Sonic 2 Beta/Final | Sonic 3

Sonic 1 (English / Portuguese) | Sonic 2 Beta (English / Portuguese) | Sonic 2 and Knuckles (English / Portuguese)
Move to Sega Retro
Number Systems (or scrap) | Assembly Hacking Guide | 68000 Instruction Set | 68000 ASM-to-Hex Code Reference | SMPS Music Hacking Guide | Mega Drive technical information