Originally Posted By: Noel96
Does the file have to be in BIAB? If so, Charlie's solution is excellent.

Just in case you are not aware of this...

In Reaper it's possible to right click on a note on the vertical keyboard on the lent (when editing MIDI) and that will select all those notes in the song.

Alternatively, it's possible to select blocks of notes.

Once notes are selected, they can then all be set to the same velocity. Regards, Noel

Sideliner: For ages Cubase, and it's predecessor Pro 24 even, had and have the Logical Editor (for MIDI data). I dunno how other DAWs function, but i often used it to edit single notes out and do all sorts of weird things to them. Alas starting my Coffee percolator won't work, but this is IMO one of the many pres Cubase has over other DAWs: