Hanoi, although the country's capital, does not give you the feeling of being in a metropolis, in fact, Saigon, the other major city of Vietnam is bigger and has more economic power. Hanoi capital is a very historical and cultural city, evidenced by the amount of craftsmanship there is. There are craft shops, some more devoted to tourism, such as souvenirs, whereas others are simple workshops where the craftsmen continue with the trade they learned from their ancestors. I can not give specific directions because they are scattered across different parts of the city.
The music shop Hong Tich is near Hoan Kiem Lake. In this store you will find "Western" musical instruments like guitars, harmonicas, etc. .. as well as folklore traditional Vietnamese instruments. There is a lack of qualified sales assistants but there is a positive to it all - negotiating prices becomes a little easier. I bought an acoustic guitar to start learning for just 14 USD.