If you post the exact dates and specific interests I would be happy to make suggestions.

tondoleo is correct the orchestra is world class but the flats are no longer a destination, and haven't been for a while now.

Start with E. 4th st which is very close to your hotel...I would suggest the Hyatt if you have any flexibility, it is at the end of E 4th and houses the chocolate bar.

Lola http://www.lolabistro.com/
Chianto http://chinatocleveland.com/
chocolate bar http://www.originalchocolatebar.com/foodmenu.php
Greenhouse Tavern http://www.thegreenhousetavern.com/

there is also

a bowling alley (corner Alley) upscale lanes and bar.

the house of blues

a comedy club (pick wick and frolic, they have a Midnight Martini
show---very "rat pack")

Irish Pub.