You can use the show mbcd statistics command to displays the number of media playbacks that are currently alive:

ORACLE# show mbcd statistics
MBCD Status                     -- Period -- -------- Lifetime --------
                      Active    High   Total      Total  PerMax    High
Media Playback             0       5       5          6       0       6

You can use the show mbcd errors command to track the number of playback failures:

ORACLE# show mbcd errors
MBC Errors/Events              ---- Lifetime ----
                        Recent      Total  PerMax
Media Playback Fails         0          0       0
Playback Exh Resources       0          0       0
Playback Flow Inactive       0          0       0
Playback Mismatch            0          0       0