building a song track after track

[ludvicek]

Hi, I am trying to record a song this way: I record a piano on track 1, than I try to record bassline on track 2: I disarm track 1 and arm track 2 and hit record and while reaper plays back track 1 it also records output from track 1 together with bass on track 2. Is there any option to stop recording the previous tracks again? I'm sure it is a stupid question but until now I've only used reaper with midi vst plugins. I use ur44 soundcard.

Thanks