Changes apply as you make them, and the tempo slider retimes playback
without redrawing a note. Under Practice there is a count-in, a
metronome click, and a speed trainer that winds the tempo up a little
every time the loop comes round. Play pauses and resumes where it left off,
each sheet has its own ▶ button to practise that exercise on its
own, and clicking any note starts playback from there. Copy link
saves the whole setup in a URL; the page also reopens with whatever you
used last.
Drop the MIDI file into any DAW or notation app (MuseScore, Logic, Ableton, Sibelius)
to slow it down, loop it, or re-engrave it. Print to PDF for a paper practice sheet.