Kosta Kolev graduated from the State Academy of Music in 1962. He studied Music Pedagogy, Conducting under Professor Georgi Dimitrov and Composition under Professor Parashkev Hadjiev. Since 1941 he played traditional music on an accordion and made his name as one of the leading traditional music performers. In 1949 he began conducting a small traditional music orchestra. In 1951 he was appointed to conduct the choir and the traditional instruments orchestra at the Ensemble for Traditional Song and Dance at the Bulgarian National Radio.

He composed songs for traditional music choir and orchestra; pieces for solo instrument or voice accompanied by ensemble or orchestra; music to dance shows; suites based on traditional Bulgarian tunes, etc. He noted down and arranged thousands of traditional songs and dances. His works were recorded at the Bulgarian National Radio and the Bulgarian National Television and released on LP and CD. They were performed by The Mystery of Bulgarian Voices Ensemble as well as by traditional music ensembles in Veliko Tarnovo, Varna, Ruse, etc.

Choral songs:
Pushka pukna (A Gun Fired); Lepa Mara Sofianska (Beautiful Mara from Sofia); Ot med li ti sa ustata (What a Sweet Voice); Izlel e Delio haidutin (Delio the Rebel Walked Out).

Songs for choir and orchestra
(1970-80):
Lechko stapiay, Done (Step Lightly, Done); Galabi gukat (Pigeons Are Crowing); Maiden Denitza; Bone le (Bone, my girl); Oy, Nedo, Nedo; Jetva se zajena (Harvest time); Prismehulka (A Tease).

Orchestral works:
Dances from Varna; Buenek Dance; The Three Times; Balkan Rachenitza; Sadovska Rachenitza; Danetz; Blatneshka Kopanitza; Petrich Dance; The lost flock (1974); Buenetzi (1979). Fantasy for solo pandore and orchestra (1973); Safeta Loves Stoyan Kehaya for kaval (Editor’s note: the kaval is a Bulgarian traditional wooden wind instrument) and orchestra (1974).

Suites:
Harvest (1971); Rhodope (1972-73); Pirin (1973); Dobroudja (1975); Pazardjik – for woman soloist, choir and orchestra (1976); Strandja; Chirpan.

Music to dance shows:
Wine Time (1978-79); Shopp Fair (1976-77); Dobroudja Dances (1975-76); Varna Dance Suite (1974); Thracians (1975).