Ya really want to know, start here, have fun radio service codes as follows AB, AI, AS, LP, LV, RP, TB, TI, TP, TS, TT
http://wireless2.fcc.gov/UlsApp/UlsSearch/searchLicense.jsp
click on the advanced search, when that page opens click the drop down box labelled service group, select broadcast auxiliary. Scroll down to the licensee information, enter Boston in the city, in the state drop down select MA, I got 159 hits, you are your own for the rest. Like I said before have fun, on thing I will add each of those 159 hits may have different freqs and locations.