He is best known for his pioneering work in the discovery, promotion, interpretation, and authentic performance of the repertoire for the 19th- and 20th-century Russian seven-string guitar.

[1] Timofeyev began his study of the classical guitar in the early 1980s under the tutelage of Swiss-Russian guitarist Kamill Frauchi [de; ru], about whom he later produced a documentary film titled Frautschi.

[3] Since 1983 he has been performing early music on authentic instruments of the plucked family (lute, guitar).

In 1989 his musical interests brought him to the U.S., where he studied with Patrick O'Brien, James Tyler, and Hopkinson Smith.

Among the fruits of his research has been his rediscovery and recording the music of Matvej Pavlov-Azancheev]] (1888–1963), who was among the rare composers for the seven-string guitar in the first half of the twentieth century.