OST is about bringing freedom of creativity to musicians and their music.

The artist of an OST or Open Source Track, has agreed to make some or all of their tracks open source, or at a greatly reduced copyright control. This means that not only can you download the fully produced track for free, but also the track's written score, guitar tab charts and the pre-mixed individual instrument tracks. OST tracks may be used for any noncommercial purpose without additional license. The artist retains the copyright to their music, and still collects royalties if the song is used commercially. Live performance of OST tracks does not count as commercial use.
Source: OpenSourceTrack.com

I have released one of the tracks from my forthcoming album as an OST already.

OST Tracks (Individual instrument tracks for remixing)
Timing is 98.5 bpm

Hope Anthem Lyrics

Guitar Chord Chart