Universal Music Group announced over the weekend that it will release a special edition of ABBA's "The Visitors" album on April 23rd.  The first release from the Sweish pop band in 18 years, the set will contain an unreleased track, "From a Twinkling Star to a Passing Angel."  Known for hits like "Dancing Queen" and "Money, Money, Money," ABBA broke up in 1982, never to reunite.  Sweden's most succesful musical act of all time, the band has sold more than 400 million albums worldwide.