Kept (i) ________ by cloying commercial radio and clueless record executives, the American popular music scene has frequently depended on cities at the edges of the cultural map to provide a much-needed shot of (ii) ________. The momentary (iii) ________ what the next big thing is seems to come out of nowhere—as if someone blows a whistle only those in the know can hear, and suddenly record executives and journalists are crawling all over what had previously been an obscure locale.
Staring with the easiest blank first
Blank(iii) will be the opposite of obscure locale so a good guess would be popular locale
Now, cloying commercial radio and clueless record executives(this is main stream thingy) are in contrast with cities at the edges of cultural map (this is the new blood / creativity / innovation etc.)
thus, blank(i) will be something related to orthodoxy or rigidness where as blank(ii) will be related to innovation and creativity . Another clue for blank(ii) is the next big thing that is after blank(ii)