MAD4clarinets is considered one of the leading quartets on the current musical scene. It consists of maestros Justo Sanz, Josep Arnau, Pablo Fernández, and Pedro Rubio.

They made their debut in 2004 at the Chamber Hall of the Canal de Isabel II Auditorium in Madrid, a concert that was recorded and broadcast on RNE. The members of MAD4clarinets participate in the most prestigious national and international festivals. Their most notable successes have been at the Offf Arteria Festival, the COMA Festival, the World Clarinet Congress ClarinetFest 2015, the San Juan de Puerto Rico Fine Arts Center, and more.

Among his performances, the most notable are the world premiere at the National Auditorium of Music in Madrid, with the Orchestra of the Community of Madrid, of Cristóbal Halffter's “Concierto a Cuatro” (2011); the premiere of the quartet version of Béla Kovács's “Homage to Manuel de Falla” dedicated by the composer to MAD4clarinets and called “À la Flamenca” within the framework of the World Clarinet Congress “ClarinetFest” (2015); and the Spanish premiere of F. Cibulka's Concerto No. 2 “Silvianum” for clarinet quartet and Symphonic Band, performed at the Teatro Monumental in Madrid with the Municipal Symphonic Band of Madrid (2016).

In June 2017, they performed at the Centro de Bellas Artes in San Juan, Puerto Rico, to critical and popular acclaim. In November 2019, they premiered the work for four clarinets and symphonic band, "Flamenquísimo in concert, Op. 112," by composer J. Susi, at the 8th National Clarinet Congress held in Valencia. In November 2020, they participated in the COMA'20 Festival with five premieres of Spanish music written and dedicated to MAD4clarinets at the CentroCentro Auditorium in Madrid.

In 2022, they presented their first recording project, Hommage à Béla Kovács, with the world's first recording in clarinet quartet versions of several of the renowned Homages dedicated to great composers throughout history by the great Hungarian clarinetist. All these quartets were written and dedicated to MAD4Clarinets.

MAD4clarinets are SELMER and Vandoren artists.