Check out these music tools. Links and a brief description are provided.
Theremin | A free touch friendly synthesizer which works great as a dub siren.
WAVE-PD1 | Another touch friendly virtual instrument.
Tibersynth | Make totally weird noises and swooshes with your mouse.
WebModular | Play a modular synthesizer in your web browser.
TrueGrid | A complex modular synthesizer with patch saving and audio export.
Tanguy | Virtual analogue synthesizer capable of processing external audio.
Patchwork | An awesome experimental modular synthesizer. Build your synth from scratch.
AngryOctopus | A collection of web-based virtual instruments (requires Java).
PatternSketch | Cool grid based sequencer with several kits and export functionality.
Tonematrix | A simple tone matrix from the makers of Audiotool.
Otomata | Another matrix sequencer for jamming and inspiration.
PulseBoy | Free Game Boy style tracker.
Seaquence | A totally weird generative music sequencer.
SiON FM Synthesizer WF-1 | Neat FM synthesizer with a mouse controlled filter.
WebSID | Browser based Commodore 64 style synthesizer.
MiniGoog | A Minimoog Google Doodle in celebration of Robert Moog's 78th birthday.
Sample-stitch | Re-create iconic hip hop tunes with your computer keyboard.
Musical Keyboard | A really simple online piano keyboard.
Online Drum Machines
FL 909 | Free Roland TR-909 emulation.
808 | A simple Roland TR-808 kit for online jamming.
Sequence | Free drum pattern generator with over 100 free drum samples.
Monkey Machine | A simple free drum machine from the creator of MauSynth.
Qwerty Beats | Online drum machine with a freaky mouse controlled synth.
JS-909 | Web based drum machine (requires QuickTime).
Drum Kit | You, your computer keyboard and 26 weird samples.
Text to Speech | Convert any text to speech and download the result as an MP3 file.
Online Tone Generator | A handy test tone generator.
Sweep Sine Tone | Sweep tone generator for testing your monitors and room acoustics.
Noisli | A wonderful background noise generator to help you relax and focus.
Defonic | Another free noise generator to help you relax.
AudioSauna | Free online workstation for making music on the go.
Soundation Studio | Online sequencer with audio and MIDI processing.
TwistedWave Online – A free online audio editor for editing mono audio files.
Podium Free | VST plugin support, limited to a single CPU core.
Indaba Music | Free online music collaboration platform.
Ohm Studio | The first free online collaboration platform for musicians.
Blend | Collaborate online and create remixes (powered by Dropbox).
Kompoz | Collaborate with musicians from around the world.
Livegit | A free online collaborative DAW.
JAM with Chrome | Jam with your friends in Google Chrome.
Plink | A fun way to pass time and make music with total strangers.
EQ Match | Simple graphic EQ trainer.
Note Ear Training | Identify notes by ear.
Pitchimprover | Absolute pitch training.
The Music Intervals Tutor | Recognize music intervals by ear.
EarTeach | Various ear training utilities.
Blind Listening Tests | Various tools to test your ears.
Interactive Circle of Fifths | An easy to use online circle of fifths.
Interactive Frequency Chart | Interactive frequency chart with an ear sensitivity graph.
Metronome Online | Free online metronome and tone generator.
Tap for BPM | A free tap tempo tool to calculate BPM.
Music Calculator | Convert BPM values, calculate transpose ratios, etc.
Tunerr | Free tuner tool which uses the microphone input on your computer.
Online Guitar Tuner | A simple online guitar tuner from Fender.
Pedalboard.js | Process the line-in of your sound card with four guitar FX pedals.
Guitar Tab Creator | An online guitar tab making tool.
Noteflight | A powerful music notation platform which runs in the browser.
Blank Sheet Music | Create and print blank sheet music for free.
Freesound Project | Download thousands of royalty free sounds.
A Sound Effect | Over 2 GB of free sound effects and field recordings in a single download.
NHF Sample Pack 002 | Over 3 GB of royalty free sounds crafted by Neurohop Forum members.
Converse Sample Library | A huge collection of stems and one shot samples, completely royalty-free.
Goldbaby | Legendary collection of free drum machine samples.
AfroDJMac | Over 100 free instrument racks for Ableton Live.
Sonatina Symphonic Orchestra | Free orchestral sample library.
NASA Audio Collection | Tons of sounds from NASA space missions. Also available on SoundCloud.
Acoustic Drum Samples | Our huge archive of free acoustic drum sample packs.
KVR Audio | Database of patches and sound banks submitted by KVR Audio members.
AudioBombs | A fresh archive of free synth patches and sound banks.
BigTick Zen | Manage and launch all your synth patches from a single plugin.
How To Make Electronic Music | An epic intro to electronic music production.
EQ Masterclass | In-depth series of EQ tutorial videos by ADSR.
Thinking inside the Box | Great beginner's guide to EQ.
Compression 101 | Great beginner's guide to compression.
Compress to impress | Compression tutorial for the electronic musician.
Kim Lajoie Blog Dump | PDF archive of Kim Lajoie's music production tips.
3 Mixing Secrets From The Legendary Andy Wallace | A reminder to keep it simple.
Synthesis Fundamentals | Free tutorials for absolute beginners by the Bob Moog Foundation.
Synth Student | Beginner's guide to subtractive synthesis.
Synthesis types | Understand different types of sound synthesis.
How To Bass | A series of tutorials for creating heavy bass sounds (by SeamlessR).
Syntorial | Software for learning synthesis. First 22 lessons are free.
Ravenspiral Guide to Music Theory | One of the finest free music theory books (here's the PDF).
Music Theory: The TL;DR Version | Music theory guide for EDM producers with short attention spans.
Music Theory for Songwriters | A comprehensive guide to music theory for songwriters.
10 Chord Progression Tips | Interesting chord progression tips from a jazz musician.
Music Theory Cheat Sheet | A handy TXT file cheat sheet for music theory.
EQ tips Cheat Sheet | EQ cheat sheet available for download in PDF format.
RealTraps | A guide to testing room acoustics with free software.
Bandcamp | Build your artist profile and share your music with your fans.
sfx.io | The Imgur of audio, an quick way to upload and share your music.
iStock | Sell royalty free stock music and recordings.
Pond5 | Another online marketplace for selling royalty free music.
Sampleism | Sell your samples and other sound design work.
Backup & Productivity
Dropbox | A great free solution for backing up your files online.
Hive | Upload and share your music and other materials.
Evernote | Take notes of all your projects and ideas in one place.
Trello | A great tool for managing your projects and collaborations.
Google Keep | Use this online note saving tool to keep track of your ideas and tasks.
Toggl | Time tracking utility to help you stay focused and measure your productivity.
Pocket | Easily save online resources (such as this article) for offline reading.
CD Cover | Make a simple CD cover with your printer and a bit of paper.
Hipster Logo Generator | A free logo generator. Also works for simple album art and covers.
Squarespace Logo | Another simple logo generator.
Pixlr | Great free online image editor similar to Photoshop.
Canva | Incredibly cool free graphics editor to make covers and promo images.
Audio Visualizer Creator 2.0v | Free music visualizer generator (requires Adobe After Effects).
Blender | Free alternative for After Effects. Loads of tutorials available on YouTube.
Strikingly | Build a beautiful looking free portfolio or artist website in minutes.
FourFour | Free website platform made specifically for musicians.
Flavors.me | Make a free artist website with links to your social media profiles.
MailChimp | Build a free mailing list for up to 2000 subscribers.
SharedCount | Monitor the social media stats of your releases or artist profiles.