My music magazine is going to cover alternative music in general, instead of focusing on one specific genre. So to come up with a name I looked up synonyms for the word "alternative", I considered a few such as unorthodox, offbeat and irregular; but was not really liking any of them. I then looked at the origins of the word alternative, and saw that it came from the Latin word "alternare" which meant interchange.
Interchange was the best word, in my opinion, up until that point, but when I thought about it I imagined a travel magazine rather than a music one. So it didn't really work as a title.
Deciding I needed a word that more specifically referenced music, I looked for synonyms for the word music, and found that they were all to technical, e.g. notes, chords, strains. So once again I looked at the origin of the word and found it came from the Greek "muse", bit since that is already the name of a fairly mainstream band, so it wasn't really valid.
In the end I just brainstormed words related to music, and thought of "Cassette" as in cassette tapes, it was a word directly linked to music, whilst also sounding pretty good and not pinning it down to a single genre of music.