It is really a shame what is happening with stores that sell musical instruments. The big music stores are able to buy stuff for lower prices because of their size. Thus they can sell it for cheaper than the small stores while making a profit. So people feel that the small stores are overcharging them, even though the small store might be operating at a loss. It causes consolidation. The little neighborhood stores are going out of business while the large stores are picking up their former customers.

As far as I can tell, there is no place in downtown Brooklyn that sell violin rosin. There used to be a place on Court Street, but they closed. So what will I do, take the subway in to Manhattan and patronize one of the giant stores? I'd rather support some independent online seller.

Update: Sep 14, 2007
This place has rosin and is an amazing place full of high-end, vintage, and exotic musical instruments. If you have plenty of money, they have plenty of wonderful things.

Retrofret Vintage, Rare & Unusual Fretted Instruments
New York String Service
233 Butler Street
Brooklyn NY 11217 USA
718 237 6092 voice/fax

This place also sells rosin:

Jalopy
315 Columbia Street
Red Hook Brooklyn
718.395.3214