If your freely recorded MIDI varies in tempo you need to do some more steps. I've done that several times.
- Cut off the MIDI Item where the song starts (or where it was counted in) and move the item completly left to measure 1
- Place a marker at measure 1 with keyboard shortcut M
- Play the song and put a marker every measure (M 2 3 4 M 2 3 4 M ...)
- Next step is a little tedious but pays of. Switch the item to inline MIDI editor (shortcut E). Turn off snapping, zoom in and move all your markers as exactly as possible to beat 1 of each measure. This will be the kick drum note mostly
- tick "Ignore project tempo, use …" in the MIDI item source properties (CTRL+F2). Leave it at 120 when your item was recorded with that tempo
- Next step needs SWS Extensions: convert project markers to tempo markers. A small self-explanatory dialogue appears. Click Convert and when you're asked to set the project timebase to time, hit yes.
- Glue the MIDI item. Done
If you want, show master track (CTRL ALT M) and delete the tempo markers. Your item follows exactly.
Additional Info is
here and
here.