actually that's all: fair price, good food, good music, cosy decor and friendly service are what 49 Çukurcuma is. that can not be explained with words, you should go and live it. it's relieving.
one of my favorites in Istanbul. I visit several times in a month, every time i find the same and the best service. the price performance is above average.
there's just one thing unnessecary: the glasses which wine is served. they should change it! :)