The Mettis String Quartet was formed in 2011 at the Lithuanian Academy of Music and Theatre (LAMT), in the quartet class of Professor Augustinas Vasiliauskas. All members - Kostas Tumosa (violin), Bernardas Petrauskas (violin), Karolis Rudokas (viola) and Rokas Vaitkevičius (cello) - are laureates of numerous national and international competitions, regularly performing solo, in chamber ensembles and orchestras, as well as participating in various musical projects and master classes. They are among the most active representatives of the younger generation of Lithuanian musical life. From the very first performances on stage, the young and ambitious quartet has been recognised as one of the most promising ensembles of the Lithuanian Chamber Music Academy.
Mettis is constantly improving its skills in masterclasses: it has participated in six ECMA sessions in Vilnius, Oslo (Norway), Grossramingh, and Graffenegg (both in Austria). Since September 2014 they have been members of the ECMA and have participated in ISA'2012 and ISA'2014 (International Summer Academy in Reichenau, Austria), where they have worked with some of the most renowned chamber music performers and pedagogues in Europe: Johannes Meissl (Artis Quartet, Austria), Hatto Beyerle (founder of the Alban Berg Quartet, Austria), Avedis Koyoumdjian (piano, Austria), Miguel da Silva, Yovan Markovich (both Ysaye Quartet, France), Jan Talich, Petr Prause (both Talich Quartet, Czech Republic/England), Peter Judt (Austria), Anita Mitterer (Mosaiques Quartet, France), Austria), Josef Kluson (Pražak Quartet, Czech Republic), Evgenia Epshtein (Aviv Quartet, Israel), Piotr Tarcholik (violin), Zdislaw Lapinski (cello) (both Poland), Paavo Pohjola (Finland), Cremona Quartet (Italy), Wolfgang Klos (viola, Austria), Per Lundberg (piano, Sweden), and others. For their successful performances at the ISA'12 competition and concerts, the quartet was awarded the prize of the Josef Haydn Institute of the Vienna University of the Arts, and at the ISA'14 Masterclasses they won two prizes - the chamber music prize and the award of the Gottfried von Einem Foundation for the best interpretation of a work by this composer. In 2016, Mettis won the 2nd prize at the 8th International String Quartet Competition in Bordeaux (France) (the ensemble was also awarded a special prize).
 In autumn 2012, Mettis was selected to participate in the masterclasses of the Villecroze Academy of Music in France, where they spent two weeks of training with the legendary Austrian pianist Alfred Brendel and the violist of the Ysaye Quartet Miguel da Silva. After gaining experience, the quartet gave its debut recital at the Museum of Applied Arts on 25 October. In December 2012, the quartet won the XII International Lithuanian Chamber Music Competition, received a special prize for its artistry and was selected to represent the Academy at the Harmos Chamber Music Festival in Porto, Portugal, in March 2013, where it performed three successful concerts. In May 2013, Mettis participated in the European Festival of Music Academies (EFAM) in Warsaw (Poland), where it represented the LAMMA. In June 2013, it was invited to perform at the 49th Plovdiv (Bulgaria) Chamber Music Festival.
The Quartet is currently actively developing its skills, working on new programmes and giving concerts. In April the quartet travelled to Oslo (Norway) and in May to the ECMA sessions in Vienna. Soon after, the String Quartet Festival in Bordeaux, France, where masterclasses and concerts were held. The quartet performed Mozart's String Quintet with Miguel da Silva, violist of the Ysaye Quartet. In June, Mettis took part in the Vilnius Festival, where he performed Mendelssohn's String Octet with the Cremona Quartet (Italy). The Mettis Quartet's debut album with works by L. van Beethoven and D. Shostakovich was recently released. In January 2016, the quartet made its debut at the prestigious Wigmore Hall in London, England.