A place worth a visit in Beijing, especially if you are interested in music is the Xinjiekou South Street. To get there, the best way is to take the PingAnLi subway station, on line 6 and line and line 4, then walk north in the street. If you are going there in tax ask for the 新街口南大街 (Xinjiekou Nandajie).
This is the traditional street for musical instruments, where yo can find many different things. You can see the shopkeepers demonstrate the traditional flutes (the Xia and the Dizi), the Erqin (kind of Chinese violin), the Guzheng (the table string instrumens you can see in period movies), the popular Hulusi (a kind of wind instrument made with a kind of Chinese calabash or bottle gourd) and Chiese lute, the Pipas. Except for these typical Chinese instruments, you may be a able to buy guitars (all kinds of), violins, pianos… The choice inside the dozens of little shops is really large, this is a place you can try the instruments, have lessons if you want to, buy music sheets etc…
Above all, this is a visit to a very traditional aspect of Beijing, which is still there in spite of the the modernization. The musical shops are resisting to the attacks of urbanization and there is really something of a genuine old Beijing there.
You’ll soon see that all of the stores have a speciality around one specific musical instrument and that you’ll be able to buy top notch things as well as bad quality, be carefum and test everything, it would be too bad to make a mistake and buy something you won’t play.
If you are going there to buy, you should be advised to take your time, some notions of Chinese can be better since sometimes best quality stuff is hidden behind the most basic ones and that they have much more than they show. Bargaining is the rule, still be aware that you have what you pay for.
If you are just there as a tourist, this is a good gate to enter the Beijing Hutongs from the west, for example via the Huguosi Hutong going eastwards, where you’ll be able to visit Mei Lanfang’s house and dine at his favorite restaurant, if you are a fan of this legendary Beijing opera singer.
If you don’t find what you are looking for here, there is another street with some musical instruments shops: Guloudong Dajie, further east, close to the Drum and Bell Tower.