The Transcribe! application is an assistant for people who sometimes want to work out a piece of music from a recording, in order to write it out, or play it themselves, or both.
It is also used by many people for play-along practice. It can change pitch and speed instantly, and you can store and recall any number of named loops. There is some advice about this in Transcribe!'s help, under the heading "Various Topics".
And it is also used for speech transcription. With its support for foot pedals and its superior slowed-down sound quality, it is an excellent choice for this purpose. There is some advice about this in Transcribe!'s help, under the heading "Various Topics".