While Ihave not been on a Seabourn cruise, my usual impression for that size of ship and the demographic is that the entertainment is pretty much geared to the senior living set - big band dance music, a salute to Rogers & Hammerstein, a classical pianist, etc.
The ships are small - 200 or 450 guests - and small ships rarely have in-depth entertainment, it just isn't that big a deal to the clientele.