Thanks for posting more information.
You can look at the staffing hours on the slow nights as set-up for the next day's busy morning. Have the staff not only cleaning up for the day, but also setting up things for the next day, such as food prep and drink recipe prep that can be accomplished early and refrigerate to keep until morning. Re-stocking all the supplies, prepping cups/saucers, plates, food displays, brewing toddys, mixing toppings/ingredients/chai, chopping and freezing fruit, and similar things can be useful tasks that are less time sensitive.
Consider music on more nights, even every night. Perhaps close earlier on Sunday through Wednesday - and stay open with music Thursday through Saturday. A 'regular' schedule pattern is more customer friendly, but a lot of businesses have extended weekend hours.
Add other entertainment on non-music nights. Perhaps game night, trivia night, darts league, knitter's cafe, duplicate bridge tournaments, chess league, family boardgames, scrabble tournament, etc, etc.
Happy hour after 6:00 p.m. on the soft nights, until business picks up, then modify the margin-reducing promos.
Try buying advertising space in the hotel elevators, or at least flyers in the lobby. Perhaps you can get the hotel to trade your advertising in exchange for a bargain rate on their coffee, or guest room gift items, or chocolate covered coffee beans instead of "mints on the pillow."
Coupons in the theater playbills should work - try 2 for 1 specialty drinks to start. The hotels may even hand out similar coupons with their room keys. Sometimes they will do cross-promotions with no real $ exchange, and sometimes it simply takes a well-placed gift of product.
If you have not had a price increase inthe past 14 months, then I recommend you increase prices ASAP. It is worth price-checking your competition, but your own COGS/margin/market position should be your strongest guidelines. I usually suggest increasing 4 to 7% per year.
Diablo is right about picking a few benchmark business measures and tracking your performance. It does not matter much which measurements you track. Pick something you can measure daily and weekly and monthly, then have your management crew track the data and post the results in an employees only location. Just monitoring your success makes your team more successful. It helps to monitor performance of some key business attribute that you want to grow. For example pick sales per man-hour, then post scheduled man-hours and results daily/weekly/monthly with a target to strive for.
You did great to thrive for 7 years, let this 7 year itch spur you on toward even greater business viability and health and happiness.