Music and Sound Utilities

MP3/OGG Music

• Audacity Open Source Windows/Linux/Mac Sound Editor
• LMMS Open source synthesizer and sequencer. Available for Linux, BSD, MacOSX and Windows. Large built in set of instruments; Variety of synthesizers; Wavetable synthesis, SoundFont, VST, LADSPA, and MIDI-in support. Renders to MP3 or OGG, among other formats.
• If you want to convert MOD music to OGG/MP3, several mod players support a 'wav' output driver which dumps the sampled music to wav, which you can then encode into the desired format. If your soundcard has a 'capture' channel, you may also be able to capture the audio output as it's playing, via Audacity; You'll probably have to manually select the Capture channel as the mic input device for this to work.
• Csound Extremely powerful open source synthesizer, sequencer, and more. Cross-platform.
• SoX A command-line program to convert and apply effects to sound files of various formats. "The Swiss Army knife of sound processing programs". Cross-platform.

Sound Effects

• sfxr provides a simple sound generation system that is capable of producing almost any simple 8bit style sound effect; For more complex sound effects you can combine sound effects with your sound editor.
• bfxr, and 'elaborated'/extended flash based version
• chiptone Sound effect generating tool (browser based, HTML5)
• LabChirp is a free program for Windows (and Mono?) for creating sound effects with lots of features
• It's also possible to use a tracker like FamiTracker to create sound effects!
• Use one of the tools in the above section to edit your sound effects files as necessary

MOD Music

• Openmpt Free windows program (works well on linux and mac using wine). Can be as simple or complex as you need it to be.
• MilkyTracker Open source, Linux/BSD/MacOSX/Windows/(other platforms. Intended as a FastTracker 2 clone, so best for composing .XMs. Imports a wide range of formats, exports MOD, XM, or WAV (so can be used to help convert modules to MP3/OGG format). Supports MIDI input. Note that the MilkyTracker's mod playback is fairly inaccurate.
• AmigaMML Open source, cross-platform. Exports MOD and XM formats. Compose music using Music Macro Language.

MIDI Music

• Anvil Studio Shareware Windows MIDI composer
• Rosegarden Open Source GNU/Linux MIDI composer
• Aria Maestosa, a MIDI editor which covers all basic needs and has a simple interface. Has various editors including percussion and score editors.
• Sekaiju A free and open source midi editor for creating and editing midi data on Windows.
• A list of MIDI sequencers
• Add more!

BAM Music

• Playbam two totally different BAM playback programs
• Notate write BAM sheet music
• MIDI2BAM convert MID files to BAM files
• BAM2MID is used internally by the OHR to play BAM as MIDIs
• Stephanie's PC Piano play your keyboard like a piano
• ABE (Amazing BAM Extractor) extract BAM music from an RPG file
• VDMSound DOS sound compatibility
• BAM Developer's Kit for programmers who want to work with BAM
• BAMTOVGM convert BAM files to VGM files

Other

• Musagi, by Dr. Petter of sfxr fame, is a tracker somewhat like ModPlug, but with more flexibility. Can be used to create NES- and Commodore 64-like chippy songs, or full fledged songs, which can be saved to WAVs. Use Audacity or SoX to convert to .ogg. Here's a good tutorial for beginners.

• Wolfram Tones Can generate surprisingly good random music based on genre, which you can then tweak with a set of included online tools.

• Bosca Ceoil is a very easy to use music editor that can be used right in your browser

• Sunvox is a multi-platform powerful modular synthesis with a tracker interface that exports to WAVs.

• Famitracker is a windows only tracker for NES chiptune.

• The Battle of the Bits lyceum has learning resources and links to various music software.

See Also

• What are the advantages and drawbacks of the different music programs?