Trying to overdub midi recording

I am trying to pull a really fast bass line out of a track but even slowing it down it is still difficult so I have set up some filters and then run into a guitar-midi converter in an attempt to pull out the notes. This works OK but I need to fiddle with the filters to get all the notes over several passes so I thought I would record the midi output and overdub so on successive runs I build up a more complete recording. I know I can do this by recording each run as a separate take but I really want to see what happens overdubbing - trouble is I just cannot get the MIDI overdub option to work. At the moment I have the original recording in one track which has the filters and the guitar-midi converter, I have then tried various ways to record and overdub the midi output but nothing works - all I have managed to do is record the MIDI output but that has no option to overdub. For instance, if I send the midi output to another track, monitor the input, select MIDI overdub, arm the track for record and then 'record' nothing happens - the track just plays. If I make the track with the recording a sub folder and use the Master/Parent send option and do the above I still get nothing. Any ideas, I am sure this must be possible.

Are you sure the track is: 1.) Receiving MIDI 2.) Set to Record: Arm 3.) Record Monitoring is ON Now make sure you did in fact right click the record button on your track and select MIDI overdub mode, and then obviously make sure you hit the record button on the transport. This should be working for you, as it works for me. Hope this helped! :)

Yup done all that. The problem seems to be that it doesnt work if the MIDI is coming from another track. I started another thread to try and explain a bit more clearly but if the MIDI is generated in one track from an audio media item and then 'sent' (either as a send or as a child to parent in a folder structure) to another track I have now found that for some reason you cannot record the incoming MIDI in the receiving track - you can however record it as outgoing MIDI (in the receiving track) but as the option for overdubbing only works on incoming I cant see how to get it to work. It looks like when you send MIDI (havnt tested audio yet) to another track it seems to bypass the point at which you record as all you get is an empty MIDI item.

You are correct, MIDI Overdub/Replace only works for MIDI Inputs (and a Receive from another track is not regarded as a MIDI Input). There have been requests for Receives to be seen as Inputs to a track. Slightly awkward workaround -- record (the MIDI Output) into separate takes on the destination track, -- explode the takes in place -- glue the items together.

Thanks for confirming that Darkstar - the workaround will do fine its just not, as you say, very elegant.

Wow, I wasn't aware of that Darkstar. That would be really handy if Reaper saw MIDI sends as inputs..