in a periodical for musicians or music buyers, in a specialized magazine or even on a big platform online
Explanation:
Nowadays you can find anything, really, quite easily. Magazines are dying, but they're still there and specialized ones might contain that sort of information. Same goes for specific sections on newspapers and, nowadays, for specific channels on web platforms. Online, there's no way you can't find something like that. In fact, it's quite easy to find almost anything that you want; specially opinions and reviews about things.