And we stayed a Saruhan Hotel (saruhanhotel.com, that family also operates the Marmara Guesthouse) in October. The places are similar, we also had a quote and offer from the Grand Peninsula. The Saruhan is slightly farther off the major sites, but only by a few hundred yards, this area is compact. OTOH, its location makes for a shorter walk to the Grand Bazaar and sites beyond. We chose it as felt it would be quieter, we went for the improved room with the city view and indeed it was fine. Breakfast excellent, staff helpful, especially in arrange to ship our jackets home after we left without them. Fantastic sunset from the rooftop dining area on our last evening.
I do believe you can throw a collection of these small hotels into a hat and pick at random and do fine. You can check reviews on Trip Advisor. Can't help you with the trad music sites, but in terms of the main attractions, you don't say when this will be but if it is in high tourist season the Musa Pass will pay for itself, possibly not in total cost savings pending what you do, but in time saved on long lines. In our opinion you do not need to arrange fancy transport to/from the airport, we obtained the transit card (note that you first get it from one machine for 10TL, of which 4 is applied to balance, and then you go to a second machine to top it, that machine puts on whatever you give it and does not make change), which did pay for itself rapidly with the reduced fares, took the Metro to the end of the line and walked 25 minutes (we are 61 and 62, packs on our backs), did not bother with the clunkier change to the Tram to save maybe 1/3 mile on foot. If you go Grand Peninsula, it is further out from the Metro end and you may wish to switch to the train at the end of the Metro, which has a stop very close to it. The walk from the tram is still lengthy, and if jet-lagged the warren of streets can be confusing. Don't forget to get your Turkish Visa online, at the airport you have lines, it's before immigration, and it costs more.
Sorry about letting this reply ramble on.