Sony ACID Pro is a professional Digital Auio Workstation (DAW) software program, originally published by Sonic Foundry, now owned and run by Sony. When it was first launched in 1998 as a loop-based music sequencer, Acid Pro was the first-ever automatic audio loop-based music software of its kind, where someone could simply drag-and-drop an Acid loop file (for example a Drum or Bass loop) onto a track in Acid, and that loop would automatically adjust itself to the tempo and key of the song, with virtually no sonic degradation.