When Music 1 stops for a violation notice during scheduling and I see: Artist 1:35, what does that mean?

When you see :  Artist 1:35  it means there is another song by that artist scheduled at 1:35 and if the song you see in the selections list were to be scheduled in the selected slot, then your artist separation rule would be violated.   So, maybe your slot to be scheduled is at 2:15 and your artist separation is one hour.  The "Artist 1:35" lets you know exactly where the other, close song by that artist is already scheduled.

steveDMCA, Rule Violations, Scheduling, 2nd