In the early to mid-1990s, Isaac, Taylor and Zac sang a cappella and recorded such classic songs as "Rockin' Robin", "Splish Splash" and "Johnny B. Goode", as well as their own material. Their first performance as a professional group took place in 1992 at the Mayfest Arts Festival in Tulsa. They were known as the Hanson Brothers, before shortening the name to Hanson in 1993. Hanson also appeared on Carman's Yo! Kidz: The Vidz, which cast Taylor as a young Biblical David facing Goliath, Isaac as an event announcer, and Zac and other members of the family in the stands cheering on this "sporting event". All three boys started their musical careers as pianists, but Isaac eventually started playing guitar and Zac started playing drums, while Taylor continued as the keyboard player. The band recorded two independent albums in their hometown of Tulsa, Boomerang (recorded in autumn 1994, released in 1995) and MMMBop (released in 1996). The latter featured the original version of the song "MMMBop", which would later become the runaway single on their debut commercial record Middle of Nowhere. The boys then found themselves at the South By Southwest (aka SXSW) music festival in Austin, Texas. There, they were promptly signed by manager Christopher Sabec. He shopped them to several record companies, most of which dismissed the band as either a novelty or fraud before Steve Greenberg, an A&R representative for Mercury Records, heard them play a set at the Wisconsin State Fair. After this performance, they were signed almost immediately by Mercury. They soon became a worldwide sensation with the release of their first major-label album, Middle of Nowhere, which was produced by Stephen Lironi and the Dust Brothers. Middle of Nowhere was released in the US on May 6, 1997, selling 10 million copies worldwide. May 6 was declared 'Hanson Day' in Tulsa by Oklahoma's then-governor Frank Keating. Although 'Hanson Day' was originally intended to be a one-time occurrence, many Hanson fans all over the world still recognize May 6 as Hanson Day every year. Hanson's popularity exploded during the summer of 1997, and Mercury Records released Hanson's first documentary Tulsa, Tokyo, and the Middle of Nowhere and their Christmas album Snowed In in the wake of their success. Hanson also launched MOE (which stood for Middle of Everywhere), a fan club magazine that ran for 12 issues. After numerous unauthorized biographies of each of the brothers were published, Hanson turned to their close friend, Jarrod Gollihare of Admiral Twin, to write their authorized biography. Hanson: The Official Book reached number 9 on the New York Times Best Sellers List (nonfiction) on February 1, 1998. The band was nominated for three Grammy Awards in 1998: Record of the Year, Best New Artist, and Best Pop Performance by a Duo or Group with Vocal. During the summer of 1998, Hanson began a highly successful concert tour, the Albertane Tour. They performed a string of shows throughout stadiums and arenas in the US, targeting young audiences with a playful and energetic style. A live album, titled Live From Albertane, was released the following fall, as well as their second documentary The Road to Albertane. In response to the demand for their earlier work, Hanson re-released MMMBop as 3 Car Garage, minus four tracks, in May 1998. To date, the tracks from Boomerang have not been re-released. Three tracks from Boomerang ("Boomerang", "More Than Anything", and "Rain (Falling Down)") and two of the remaining tracks from MMMBop ("Incredible" and "Baby (You're So Fine)") were released on the first MOE CD sent to fan club members. During the Albertane Tour, Hanson wrote and demoed what would later become the songs for their second major studio album, This Time Around. During this time period, Mercury Records, the band's label, had been merged with Island Def Jam. Almost immediately following the changeover in May 2000, Hanson released their second album, This Time Around, but due to lack of promotional funding, sales were low and the label eventually pulled funding for their tour. The band toured through the summer and fall of 2000 on their own funds. After a three-year struggle, the brothers left Island Def Jam Records to seek more creative freedom. Label executives had refused over 80 songs from the band, believing new material lacked marketability. The documentary film Strong Enough to Break follows these events. Hanson now records for their own independent label, 3CG Records. The label has distribution deals through Alternative Distribution Alliance in the United States, Cooking Vinyl in Europe, Sony Music in Asia and with various other distributors throughout the world. During the dispute with their former label, Hanson signed with the management company, 10th Street Entertainment, which also manages artists such as Meat Loaf and Blondie. The band's Underneath Acoustic tour occurred during the Summer and Fall of 2003. Music included acoustic versions of songs from the then-forthcoming release, Underneath. The tour ended November 5, 2003 with a performance at Carnegie Hall. Released on April 20, 2004, Underneath sold 37,500 copies in the first week of release in the US alone. The album debuted at No. 1 on Billboard Top Independent Albums chart and No. 25 on the Billboard 200 album chart, making Underneath one of the most successful self-released albums of all time. In autumn 2005, Hanson toured in the US and Canada to support The Best of Hanson: Live & Electric. They also visited colleges to showcase Strong Enough to Break, the documentary chronicling difficulties with and departure from Island Def Jam. During college visits, the band held question-and-answer sessions about independent artists' role in the music industry. CANNOTANSWER

Answer this question "What did they release under the mercury label?" by extracting the answer from the text above.

They soon became a worldwide sensation with the release of their first major-label album, Middle of Nowhere,