Question: What genre of music  did Loudest Whisper debut on a vinyl record format characterized by a speed of 33 ⁄ rpm, a 12 or 10 inch (30 or 25 cm) diameter, and use of the "microgroove" groove specification?
Sentence (from "LP record"): Apart from a few relatively minor refinements and the important later addition of stereophonic sound, it has remained the standard format for vinyl albums.
Relevant evidence: No