Editing ROM hacking (section)

===Music hacking===
Music hacks are relatively rare in most hacks, due to the wide variety of ways games store music data (hence the difficulty in locating and modifying this data) as well as the difficulties in composing new music (or porting music from another game). As music cracking is very uncommon, many hacks do not have any ported/composed music added in. Exceptions exist, however, such as the most recent ''[[Super Mario World]]'' hacks where custom music can have new instruments not found in the original game. Other games that have music hacking as part of their research and hacking communities are the NES ''[[Mega Man]]'' games, ''[[Final Fantasy VI]]'', and the Mega Drive (Genesis) ''[[Sonic the Hedgehog]]'' games.

As many Game Boy Advance games use the M4A Engine (informally called "Sappy Driver" and officially known as "MusicPlayer2000" or MP2k) for music, the program SapTapper can be used to hack Game Boy Advance music data. Various other utilities were created to work with the engine such as [https://web.archive.org/web/20160306150654/http://www.pokemonhackersonline.com/showthread.php?t=120-Wataru-Kun-s-Ultimate-Pok-mon-Music-Hacking-Guide Sappy 2006]. Another instance of the same engine being used between games is on the Nintendo 64 where most games use the same format; albeit with different sound banks for each game. A utility known as the [https://github.com/jombo23/N64-Tools/tree/master/N64MidiTool N64 Midi Tool] was created to edit the sequences that the majority of Nintendo 64 games use, however it does not cover first-party N64 titles that use a slightly different engine such as ''[[Super Mario 64]]''.

On the Sega Mega Drive (Genesis), several games made for the system had its music and sound effects created under a single sound engine commonly known as "SMPS" (also known as "Sound-Source" by some developers), which has been offered in both [[Motorola 68000|68000]] and [[Zilog Z80|Z80]]-based versions.<ref>{{cite web|url=https://vgmpf.com/Wiki/index.php?title=Mega_Drive/Genesis_Sound_Driver_List#Sega|title=Mega Drive/Genesis Sound Driver List|website=Video Game Music Preservation Foundation}}</ref><ref name="smps">{{cite web|url=http://segaretro.org/SMPS|title=SMPS|website=Sega Retro}}</ref> This sound engine, leveraging both the [[YM2612]] and [[SN76489]] sound chips of the console, was predominantly used in a wide variety of Japanese-developed games for the system (including Sega's first-party games),<ref name="smps" /> with some games providing modified versions of the sound engine tailored to a specific game. The SMPS engine has been researched for decades by many hackers,<ref>{{cite web|url=http://forums.sonicretro.org/index.php?showtopic=32473|title=Valley Bell's SMPS Research|website=Sonic and Sega Retro Message Board|date=December 31, 2013}}</ref> which led to the creation of various utilities<ref>{{cite web|url=http://info.sonicretro.org/Sonic_Hacking_Utilities#Sound_Editors|title=Sonic Hacking Utilities|website=Sonic Retro}}</ref> that can alter and create music (and sound effects) for games using the SMPS engine (most notably the ''Sonic the Hedgehog'' games in particular); many of the compositions and arrangements made under the SMPS engine had eventually made their way onto the [[Steam Workshop]].<ref name="steamworkshopsmd">{{cite web|url=http://steamcommunity.com/workshop/about/?appid=34270|title=Steam Workshop :: SEGA Mega Drive & Genesis Classics|website=steamcommunity.com}}</ref>