Taeyang invited the girl who did a cover of his song and that he reposted on Instagram on to the stage at the concert in Los Angeles.
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Taeyang found a cover on YT by this fan of "Wake Me Up" & he brought her out to sing!! ( he likes this type of voice (FD) ) #WHITENIGHTinLA pic.twitter.com/ibsgiLP3Tg— ???????? (@staygold0624) September 13, 2017
Source: as tagged and as visible on hover-over and in title of enlarged photo.