While the MIDI features of version 3 could perhaps best be described as 'basic', all the new features were certainly very usable and, despite obvious competition from the likes of Sonar, Acid 3 is an excellent creative tool, either used on its own or sync'ed to a MIDI + Audio sequencer.Ī year later, Acid Pro v4 is upon us. SOS last looked at Sonic Foundry's Acid Pro in January 2002 when, in addition to the core functionality based around pitch- and time-stretching of audio loops, new features included MIDI tracks, a Video window and two new tools: the Beatmapper and the Chopper. With the addition in version 4 of surround sound mixing, ASIO and VST Instrument support and an expanding MIDI functionality, Sonic Foundry are attempting to move Acid beyond its original role in loop-based music creation. The user interface of Acid Pro v4 contains all the elements familiar from earlier versions of the software.