Linux MultiMedia Studio (LMMS) is an excellent freeware music creation application which competes with commercial products like Fruity Loops. Even though the name implies that it is a Linux-only application, there is infact a Windows port which runs perfectly.
The main application of LMMS is able to edit beats, loops and MIDI sound tracks and is able to apply a number of special effects to your music projects. In addition to editing music, it can playback the tracks you're working on also in edit mode.
Version 1.1.3 is a freeware program which does not have restrictions and it's free so it doesn't cost anything.
Virus and Malware Tests: The program has been tested with several antivirus applications and has tested clean of viruses, malware or trojans.