This walkthrough shows how to build a MIDI clip in Ableton Live from scratch, no hardware controller required. Double-click an empty clip slot to create the clip, then use the piano roll on the left side of the Clip view to see and edit notes on a familiar keyboard layout that you can resize and scroll through.
Enable the MIDI Editor preview button so you can hear notes as you place them. Double-clicking directly in the piano roll drops in a note at that pitch and position, or you can hit B on your keyboard to switch to the Pencil tool for faster note entry with the mouse.
Once notes are in, hit Launch to play back the clip and check your sequence. Right-clicking any note opens a menu with editing options like Quantize and Quantize Settings, useful for tightening up timing without needing to play anything live.