"Lounge music" was once a pejorative term: It called to mind blowsy has-beens warbling off-key Peggy Lee covers while slumped against a baby grand at the airport Ramada. That changed last decade, when the increase-the-beats approach to dance music birthed the chill-out room, where revelers could recharge in advance of the next 120-BPM cardiac challenge. Today, the music invented to fill the latter space is an intrinsic part of club culture, and acts such as Bitter:Sweet ensure that it goes down smoothly. Kiran Shahani, once in the Supreme Beings of Leisure, handles the backdrops, opting for warm sonic swells that caress the vocals of Shana Halligan, whose cooing typically remains in the middle ranges — the sonic comfort zone. The duo's latest disc, The Remix Game, features versions of material first heard on 2006's The Mating Game as reconfigured by a gaggle of high-rent mixologists, including Nicola Conte and the Thievery Corporation. The results are alluring enough to make dancers remain in the lounge long after their heart rates have returned to normal.