[BScout]

To quote from the manual

If a record-enabled track is in Auto Input
Monitor mode, you will hear “through” the
input while the Transport is stopped. The
track automatically switches to playback
when you press play, then back to Input
mode when you either stop, or punch into record.
For more information, see “Auto Input
Monitoring” on page 511.

Which means the I isn't lit but the R is when in record

This is what you want and then you want to be in quick punch/track punch record mode verses normal record. See Chapters 24 and 26 in the manual about all the options on record modes.
Then you hit play and the track plays back what is there until you punch in for record and then it switches to the recording until you punch out again.