The Apply tool is a utility for taking multiple phrases and applying their attributes to some target phrase. The PH1 , PH2 , PH3 , and PH4 buttons let you read four phrases (either from Standard MID Files, or from the Snarf). The Apply button lets you load the target phrase (from Standard MIDI Files, or from one of the other four phrases). The Apply button then is used to apply the attributes (such as pitch, duration, or timing) from the other phrases to this target phrase.