Beware that using groups clould change your reverb vs dry balance if you are using fx returns not routed to this groups. Common way to solve this is route fx returns also to the music group you are lowering or changing in level, and use a seperate reverb for each group and your input, routed to mix out.
An easier and better solution is using a vca for all music that you want to control.(select channels>right mouse click>ad vca channel to selected channels) Do not include fx returns or the tracks you are recording. The vca will control the level of all selected channels directly but will preserve the relative balance.
In the link options set it to vca only. Restoring the original mix is easy: reset the vca to 0db.
Also a verry handy tool to control a hot mix, or music vs vocal balance…