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?
LP record The LP (from "long playing" or "long play") is an analog sound storage medium, 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. Introduced by Columbia in 1948, it was soon adopted as a new standard by the entire record industry. Apart from a few relatively minor refinements and the important later addition of stereophonic sound, it has remained the standard format for vinyl albums.
Mini-LP A mini-LP or mini-album is a short vinyl record album or LP, usually retailing at a lower price than an album that would be considered full-length. It is distinct from an EP due to containing more tracks and a slightly longer running length. A mini-LP is not to be confused with the unique to Japan "mini LP sleeve" or "paper jacket" CD.