Success has its drawbacks. Once your competitors figure out what you’re doing, you become everyone’s favorite target. Lower your guard, and your lead can suddenly evaporate. That’s the challenge faced by Sony Media Software’s ACID Pro, which is still the best environment for generating loop-based music. ACID Pro’s success is based partly on the quality and diversity of its loop collections, though that becomes less of an advantage as competing programs add support for ACID-compatible loops. The other reason? It’s intuitive. Anyone can create a catchy tune with only an hour or so of training.

It has been almost three years since the release of ACID Pro 4. During that time, SONAR, Cubase and Live have added extensive support for ACID files. They have also introduced features that aren’t yet available in ACID Pro-mostly notably, Live 4’s ability to manage variable-tempo loops in real time. That’s why ACID Pro 5 was greatly anticipated. Would the king of the hill regain its vigor, or continue to lose its edge?

If you were expecting a wheelbarrow-full of new features, you may be disappointed. On the other hand, Sony has added many of the features users have been clamoring for, such as support for VST effects, tempo-based DirectX effects and ReWire-compatible devices; beefed-up MIDI editing; custom file tags for improved media library searches; and enhanced audio time stretching. The VST effects support includes automation of effects parameters, tempo mapping and the application of VST soft synths across multiple busses. You could combine dynamic VST effects with bus-to-bus routing to change the music as it progresses over time or as it physically moves through the surround mix.

Perhaps the most powerful new additions to ACID Pro are the Groove Mapping and Groove Cloning quantization tools. You know how frustrating it is when your perfectly cut loops don’t sound quite right when mixed together? Groove Mapping lets you apply any of 50 grooves (such as Bounce or New Orleans Swing) to alter the rhythmic feel of your loops and MIDI files, evening out the rough edges. Groove Cloning lets you extract the groove from one file and apply it to another.

The quantization tools-like the other tools in ACID Pro 5-are real time and non-destructive. You can selectively tweak, apply and layer them until you find the precise sound you’re looking for. As you might expect, you’ll need a musical ear to achieve the best results. ACID Pro is widely used by top recording artists, music composers and audio production professionals. In theory, it’s all you need to craft music tracks worthy of a blockbuster movie.