If you're looking to make your own beats but just don't have any money at all to spend, you might find this list of legal beat making software very useful. This music software list does not include plug-ins and I did not try out each one of these. I did the research to find them, you can do the research to find which is best for you. :)
Note that some of these beat making software versions are "lite" versions and have commercial version as well. Have fun with this list of music making software!
Digital Audio Workstations
ACID Xpress (windows)- This is a 10-track version of ACID Pro software. It can do music recording, editing and mixing. Making beats is easy with this loop based software. ACID Xpress has an excellent ability to match the tempo and pitch automatically. I was a big ACID Pro user when I first started and it helped me to visualize how audio can be arranged. I didn't use the audio recording much back then. This is one music making software that I will have to revisit.
LMMS (linux/windows) Linux MultiMedia Studio - it looks like FL studio but is not FL Studio compatible. It can run on Linux and Windows based computers. You can make beats, compose melodies, mix master and more with this cool little freebie. Music making software like this is a welcome find.
Koblo (mac/windows) A very new player on the block. It's another free open sourced audio recording and music making software. It has some unique online collaboration features, because it's connected to the Koblo cloud. You'll be able to work together with other musicians or band members across the planet.
Anvil Studio (windows) Can do audio and MIDI sequencing. Looks a little old, but hey of the audio sounds fresh, who cares what it looks like!
Kristal (windows) This music making software has been around for a few years now. it hasn't been updated in a while from what I can tell but it has a lot of features.
Music Studio Independence (windows) has a great number of functions for every part of beat making, such as composition, arrangement, audio recording, mixing and mastering. It handles MIDI and audio. One awesome looking music making software.
MultitrackStudio (windows) This is an audio/MIDI multitrack recording software for Windows. It combines a multitrack audio recorder, a mixer, lots of effects and a MIDI sequencer in one package: everything that's needed to turn your computer into a digital multitrack music recording studio and beat making device.
MU.LAB (mac/windows) Marketed as an alternative, state of the art software application for OSX and Windows, transforming your computer into a real music studio! It does not overwhelm you with a complex feature set, in which you can get lost. Sounds perfect for a new beat maker.
Quartz (windows) This is one I have heard about but the website product page was down when I researched it. The home page makes a reference that it runs under Vista so I assume it still being developed. I hope to learn more abou this music making software.
MusE (linux) is a Linux based MIDI/Audio sequencer with recording and editing capabilities written by Werner Schweer. MusE aims to be a complete multitrack virtual studio for Linux, it is published under the GNU General Public License. MusE has among other things support for MIDI, Audio Effects, etc.
Ardour (linux/mac) is a digital audio workstation. You can use it to record audio, edit and mix multi-track audio recordings. You can produce your own CDs, mix video soundtracks, or just experiment with new ideas about music and sound.
Rosegarden (linux) is a well-rounded audio and MIDI sequencer, score editor, and general-purpose music composition and editing environment. Rosegarden is an easy-to-learn, attractive application that runs on Linux, ideal for composers, musicians, music students, and small studio or home audio recording environments.
Audio Recording and Wave Editors
Quick Audio (windows) A full featured audio recording and manipulation program that lets you edit, play and record digital audio as well as convert between various popular audio formats. It has standard audio editing features, multiple undo, audio spectrum analysis as well as support for up to 24 VST plugins.
Wavosaur (windows) is a free sound editor, audio editor, wav editor software for editing, processing and recording audio sounds, wav and mp3 files. Wavosaur has all the features to edit audio (cut, copy, paste, etc.) produce music loops, analyze, record, batch convert. Wavosaur supports VST plugins, ASIO driver, multichannel wav files, real time effect processing.
Freecycle (linux) is a beat slicer running on GNU/Linux platform using the QT toolkit, providing amplitude domain and frequency domain beat matching / zero crossing algorithms. It exports sliced audio chunks and generates a MIDI file which can be used to play the sliced loop, or you can jam with it as soon as you’ve made slices using a midi keyboard or sequencer.
WaveSurfer (linux/mac/windows) is an Open Source tool for sound visualization and manipulation. It has been designed to suit both novice and advanced users. Probably not as useful for your average beat maker, but the price is right.
Sweep (linux) is an audio recording editor and live playback tool for GNU/Linux, BSD and compatible systems. It supports many music and voice formats including WAV, AIFF, Ogg Vorbis, Speex and MP3, with multichannel editing and LADSPA effects plugins.
Audacity (linux/mac/windows) This is more of an audio recording editor but it can do multiple tracks. it's open source and can run on Mac/PC (Windows) and Linux. It has many advanced features and can use plug-ins. This is probably better used a sampler for you beat makers out there. For free music software this is the best wave editor out there.