The 66music tool bench
66loops
Upload any recording and loop any section of it to jam along — everything stays in your browser. The analysis tells you what it hears (bars, silences, rhythm) with its confidence, and transcribes single-line phrases to a MIDI file you can take anywhere. What it cannot honestly do — untangle chords into notes — it says plainly instead of guessing.
66loops needs an account
66loops is free with an account. A free account gives you exercises 1–11 of every set, the metronome, the loops and the tuner — no payment details, just an email.