Performing with US rock group, also inside awaiting a hearing (2,6)
'inside awaiting a hearing' is the definition.
(in prison awaiting a hearing)
'performing with us rock group' is the wordplay.
I cannot really understand how this works, but
'performing' could be 'on' (as in being on stage) and 'on' is found in the answer.
'with' could be 'and' and 'and' is found in the answer.
'rock group' could be 'rem' (REM are a US rock band) and 'rem' is found in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
'also' acts as a link.
Can you help me to learn more?
(Other definitions for on remand that I've seen before include "Not yet tried", "officially not out", "Status of some prisoners", "awaiting court's decision?", "yet untried".)