Inventive singer-songwriter and guitarist Emma-Lee Moss has been a part of London’s anti-folk movement for close to a decade, performing with Noah and the Whale and Lightspeed Champion, and doing her own thing as Emmy the Great. Her debut full-length, First Love (stream it below), written on the heels of a breakup, came out in 2009 to some considerable plaudits. According to Drowned in Sound, “Emmy the Great’s debut is a triumph, with a maturity beyond her years, and with a humor no less enjoyable for being subtler.” Virtue (stream it below) arrived two years later, again following a breakup—this time the dissolution of an engagement. And again critics were impressed. BBC Music labeled the LP “a dense, accomplished set of songs” and “an extraordinarily confident work, shaped by confusion and turmoil.” Emmy the Great (above, doing “Paper Forest: In the Afterglow of Rapture” for Amazing Radio) recently returned with a new EP, S (stream it below), about a month ago. Per Drowned in Sound, “This is the richest, most musically complex she has ever been…. Even that voice has learned tricks, becoming jazzier and more experienced sounding. It’s quite something.” Of course, Emmy the Great is quite something when performing live. And you can catch her doing just that tomorrow night at Mercury Lounge. Electro-pop duo Clementine and the Galaxy opens the show.