Free+Software

=//MuseScore//=

http://musescore.org/en

media type="youtube" key="0mh6m2mbVHs" height="390" width="480" //MuseScore// is a free cross platform WYSIWYG music notation program, licenced under GNU GPL. Some highlights:
 * WYSIWYG, notes are entered on a "virtual note sheet"
 * Unlimited number of staves
 * Up to four voices per staff
 * Easy and fast note entry with mouse, keyboard or MIDI
 * Integrated sequencer and __[|FluidSynth]__ software synthesizer
 * Import and export of __[|MusicXML]__ and Standard MIDI Files (SMF)
 * Platform independent code, binaries available for Windows, Mac and Linux
 * Available in __[|20 languages]__
 * GNU GPL licenced

=Audacity= http://audacity.sourceforge.net/

**The Free, Cross-Platform Sound Editor**
Audacity® is free, open source software for recording and editing sounds. It is available for Mac OS X, Microsoft Windows, GNU/Linux, and other operating systems.

**Linux MultiMedia Studio**

http://lmms.sourceforge.net/home.php Windows and Linux Versions available

LMMS is a free cross-platform alternative to commercial programs like FL Studio®, which allow you to produce music with your computer. This includes the creation of melodies and beats, the synthesis and mixing of sounds, and arranging of samples. You can have fun with your MIDI-keyboard and much more; all in a user-friendly and modern interface.

Features

 * Song-Editor for composing songs
 * A Beat+Bassline-Editor for creating beats and basslines
 * An easy-to-use Piano-Roll for editing patterns and melodies
 * An FX mixer with 64 FX channels and arbitrary number of effects allow unlimited mixing possibilities
 * Many powerful instrument and effect-plugins out of the box
 * Full user-defined track-based automation and computer-controlled automation sources
 * Compatible with many standards such as SoundFont2, VST(i), LADSPA, GUS Patches, and MIDI
 * Import of MIDI and FLP (Fruityloops® Project) files