March 2005, he recorded and released the duet "All (I Ever Want)", an English version of the 3 Musketiers theme song featuring vocals from German singer Sabrina Weckerlin. The original version of the duet, "Alles" was released to promote the RTL television film Held der Gladiatoren (2005). The English version of the song peaked at number 12 on the German Singles Chart was later included on his third album, Attention! (2006). Recorded after a short-living hiatus from recording in which she had studied song and acting at the Joop van den Ende Academie in Hamburg, it marked a departure from Klaws's previous work with Bohlen, who gained no credit on the record. Instead, Klaws consulted a wider range of producers to work with him on the album, including Terri Bjerre, Thorsten Brötzmann, and Ivo Moring, who took his work further into the pop rock genre. Upon its release, Attention! became a top 20 success in Austria and Germany only, prompting Sony BMG not to release another single from the album. 2007–present: Musical theatre In December 2006, Klaws made his musical theatre debut at the Theater des Westens stage in Berlin in 2006, playing the role of Alfred in the musical remake of Roman Polanski's satirical horror drama Dance of the Vampires (1967). Following the conclusion of his management and recording contract, he signed a new deal with Cruiser Entertainment which released his fourth album Was willst du noch?! through Edel Music in April 2008. His first album to be primarily recorded in German, it peaked at number 28 on the German Albums Chart and produced two singles. In 2010, Klaws took over the role of Tarzan in the Neue Flora Hamburg production of the same-titled musical based on the Walt Disney Animation Studios 1999 film of the same name. Running for five years, it closed in 2013. Klaws collaborated with frequent collaborators Thorsten Brötzmann and Ivo Moringa on his fifth album Für alle Zeiten. Released in September 2011, it reached the top fifty of the German Albums Chart and produced several singles, including "Himmel und Hölle". In April 2013, he served as a supporting act throughout the German leg of British singer Leona Lewis's Glassheart Tour. The same year, Klaws played the role of Ranger in the musical version of the German comedy film Der Schuh des Manitu at the Freilichtbühne Tecklenburg. He returned to Tecklenburg the following year, portraying