Question: Who rejoined the Backstreet Boys who was also inducted into the Kentucky Music Hall in April 10, 2015?

Kevin Scott Richardson (born October 3, 1971) is an American singer, songwriter, actor and model, best known as a member of the Backstreet Boys.  Richardson was inducted into the Kentucky Music Hall of Fame along with his cousin and bandmate Brian Littrell on April 10, 2015. <SEP> "Bigger" is a song by American boy band Backstreet Boys.  It was released on November 29, 2009 as the second single from their seventh studio album, "This Is Us" (2009).  The song was co-written and produced by collaborator and producer Max Martin.  This was the last standard Backstreet Boys single released before Kevin Richardson rejoined the group.  The band stated that the song was one of their best hits since "I Want It That Way", a song written and produced by Martin for the band in 1998. <SEP> Backstreet Boys: Show 'Em What You're Made Of is a 2015 American documentary film about the career of the American vocal group Backstreet Boys, released on January 30, 2015 in the U.S., and was released on February 26, 2015 in the UK and Europe, and March 28, 2015 for the rest of the world.  It was directed by Stephen Kijak. <SEP> The Lonesome Pine Fiddlers (1938- 1966) were an early bluegrass band which included such notable "first generation" bluegrass musicians as Ezra Cline, Bobby Osborne, Paul Williams, Melvin Goins, Charlie Cline, Curly Ray Cline, Larry Richardson and for a short time Jimmy Martin.  The group was started by Ezra Cline and Curly Ray Cline and was originally named "Cousin Ezra and the Lonesome Pine Fiddlers".  The Clines came from a large family consisting of musically talented people.  Ray and Charlie's father, Charlie, was a talented banjo player and the women in the family, Geraldine and Bobbi, were great singers.  For reasons unknown, Bobbi and Geraldine never joined the band on the road but often joined in at home, especially when notable Country singers, such as Bill Monroe, Lester Flatt and Earl Scruggs, and Hank Williams, came visiting.  None of them ever had a music lesson yet excelled on every instrument they touched.  Natives of the Gilbert Creek region of southern West Virginia, Cousin Ezra, along with brothers Ireland (Lazy Ned) and Curly Ray Cline, were part of the original Lonesome Pine Fiddlers from about 1938, a group that worked on radio at WHIS Bluefield, West Virginia.  During World War II, Ned was killed in action.  When the Pine Fiddlers resumed regular daily broadcasts, Charlie, who played multiple instruments, joined them on a regular basis.  Charlie returned to the Fiddlers briefly before becoming a member of Bill Monroe's Blue Grass Boys.  During 1952-1955, Charlie worked off and on with Monroe, recording some 38 songs, all on Decca.  It has been said that he played every instrument at one time or another in the Monroe group except mandolin.  Charlie spent most of 1953 back with the Lonesome Pine Fiddlers working at WJR radio in Detroit.  When Ezra brought the band to Pikeville, Kentucky, in November, Charlie rejoined Bill Monroe.  In 1954, Charlie did a session, playing lead guitar, with the Stanley Brothers and also another one on RCA with the Fiddlers, although he was not otherwise working with them at the time.  He also worked briefly as a sideman with the Osborne Brothers, although he did not record with them.  By 1958, Charlie (electric lead guitar) and his wife, Lee (electric bass), had rejoined Ezra and Curly Ray in the Lonesome Pine Fiddlers, who were experimenting with a more modern sound and working a TV show in Huntington, West Virginia, in addition to daily radio in Pikeville.  In his later years, Charlie was with the Stanley Brothers.  Curly Ray also played with the Stanley Brothers at a different time as their fiddler.  Curly Ray was one of the best fiddlers in Bluegrass.  This most talented family of musicians were the best, surpassed by none.  Finally, on October 1, 2009, The Lonesome Pine Fiddlers got their due when they were inducted into the International Bluegrass Hall of Fame at the Ryman Theater (the original home of the Grand Ole Opry).  Bobby Osborne, Melvin Goins and Paul Williams were there to receive the bands award.  In the crowd of a sold out theater was the son of Ezra Cline, Scotty Ireland Cline, who recalled being in that same theater as a child sitting on stage and watching the Fiddlers play.  (At the time, the Opry had bleachers for family just off stage).  The final act of the evening at the IBMA Awards was the playing of "Pain in my Heart" by Osborne, Goins and Williams along with a Song from the Dillards, who were also inducted the same evening.