Education
Later, he moved to Salzburg, where he attended its college and studied with Sándor Végh.
Later, he moved to Salzburg, where he attended its college and studied with Sándor Végh.
He also works as a director and conductor of Concerto Budapest. During the same time, he worked as a soloist for the National Philharmonia and from 1984 to 1991 was the Budapest Festival Orchestra"s leader. He has performed with Heinz Holliger, Ralph Kirshbaum, Gidon Kremer, Mstislav Rostropovich, among others
Keller has performed György Kurtág"s works worldwide and conducted the Orchestra di Padova e del Veneto in 2013.
During the same years, he appeared with Kremerata Baltica at the Lockenhaus Festival and was a director of the Arcus Temporum Festival from 2005 to 2009.