Mehmet Okonşar was born in Istanbul (Turkey) and lived in Paris during his first schooling. He started studying piano at the National Conservatory of Ankara, with Nimet Karatekin and Necil Kazim Akses. Thanks to the rich resources the Ankara Conservatory then possessed and the Médiatheque of the Centre Culturel Français d'Ankara, he grew up studying the music of Pierre Boulez, Edgar Varėse, Olivier Messiaen and Pierre Schaeffer, composers which would have a strong influence on him.
After about a year and half studying at the Ankara Conservatory, the family moved to Belgium where he entered the class of Jean-Claude Vanden Eynden at the Brussels Royal Conservatory of Music. Vanden Eynden, who ill entirely re-shape the keyboard technique of Okonşar, is a dedicated follower of the style of Eduardo del Pueyo.
A change of Government in Turkey and the political turbulences of 1977 forced Okonşar family to return to Ankara. Back at the Ankara Conservatory he is put in the class of Gülay Uğurata for the piano and of Nevit Kodalli for musical composition. Okonşar did not attend with any assiduity in either class.
During this period he connected on both friendly and professional basis with the pianist and conductor Selman Ada. From this friendship he learned the basics of the keyboard principles of Pierre Sancan of whom Selman Ada has been a student.
Just before the military coup of 1980 the Okonşar family returned to Belgium. He resumed studying with Jean-Claude Vanden Eynden. In 1980 Okonşar was rewarded the Premier Prix avec Distinction. His program included the Dante Sonata by Liszt. His studies continued after the sudden death of his father with a special scholarship and he got the  de Piano Avec la plus Grande Distinction, Premier Nommé in 1986 by performing the Piano Concerto Op. 42 by Arnold Schoenberg.
At the end of his piano studies, Okonşar had the privilege of working with one of the greatest composers of Belgium: Madame Jacqueline Fontyn. He also studied with a pupil of Messiaen, Claude Ballif. In 1989 he gets his degrees in Composition-Orchestration from the Royal Conservatory of Music of Brussels.
He endorsed the Belgian citizenship in 1992 but at the same time the President Suleyman Demirel of Turkey rewarded him with the title "State Artist of the Turkish Republic". Therefore Okonsar will settle in Turkey with his wife Lale Okonşar, painter.
Okonşar works now from Turkey on a busy schedule concertizing, composing, writing and teaching. He owns and manages a CD label exclusive to his own recordings, LMO-Records, and a publishing company "inventor-musicæ."
His international career began with the first prize at the International Young Virtuoses Competition of Antwerp in 1982. His orchestral début was the Third Concerto by Rachmaninoff performed at the deSingel Concert Hall in Antwerp. His other prizes are: Paris, 1989, "J. S. Bach" at the Salle Gaveau: second prize; 1990, Rome, Association Chopin "Premio Etruria": first prize; and 1991, United States, Utah, the sixth prize at the "Gina Bachauer International Piano Competition".
The "Académie des Arts Contemporains" of Enghien, Belgium rewarded him in 1991, for his acoustic and electronic compositions the Gold and Bronze medals respectively.
Mehmet Okonşar performed with the following orchestras: Utah Symphony, Antwerp Philharmonic, Poznan Philharmonic and Lublin Philharmonic. Some of the conductors he played with: Joseph Silverstein, Charles Dutoit, Sylvain Cambreling, Ingo Metzmacher, Christof Escher.
In recital he appeared at London's Royal Opera House, the Salle Gaveau in Paris, in New York, San Francisco, Tokyo, Kyoto, Bruxelles, Anvers, Amsterdam (Concertgebouw), Rotterdam, Rome, Athens, Calgary, Salt Lake City, Ljubljana.
He has been a guest judge at the National Piano Competition of Japan under the auspices of the P.T.N.A. (“Piano Teachers National Association”). His researches on music and technology were presented in a lecture at the Yamaha headquarters in Hamamatsu, Japan. Okonşar wrote and presented a documentary series on the National Television Broadcast of Turkey, the T.R.T.
Okonşar is a published writer in several music related periodicals in Turkey. His articles published in Andante the most important Turkish periodical on classical music, were featuring imaginary interviews with "Mephisto" on the subject of the global decadence of the quality of classical music, in Turkey and in the world, a subject often worked on by Okonşar. His other published subjects are mainly about musical composition, analysis, music history. Okonşar publishes also in English and French.
His repertoire encompasses a range from the early 17th. century ("The Fitzwilliam Virginal Book") including among others Orlando Gibbons and Giles Farnaby and extends to late 20th. century with the works by Karlheinz Stockhausen and Witold Lutoslawski. Notable works in this repertoire are: J.S. Bach "The Art of Fugue" performed on organ (or piano) and harpsichord; the Goldberg Variations, the integrale of Well-tempered Keyboard.
Okonşar has performed recitals featuring the complete piano works by Arnold Schoenberg, Alban Berg and Anton Webern. Despite he refuses all sort of "musical specialization", his repertoire is heavily on the "modern" side with Igor Stravinsky "Three Movements of Petrouchka" the "Sequenza" for the piano by Luciano Berio and the Klavierstücke by Karlheinz Stockhausen.
Solo piano published by his own (artist-managed, independent) label "LMO-Records":
- Last name: BACH: Selected piano works by Carl Philipp Emanuel Bach, Johann Christian Bach and Wilhelm Friedemann Bach (piano)
- F. CHOPIN: Etudes, complete op.10, op.25 and "Trois nouvelles études" (piano)
- J.HAYDN: Last four piano sonatas (piano)
- J.S.BACH: Toccatas (BWV 910-916) (piano)
- "Schumann-Fantasie": the Fantasie in C major, op.17 and the "Études Symphoniques" op.13 by Robert Schumann, including the "Five additional etudes" op. post. published by Johannes Brahms after Robert Schumann's death.
- "Liszt-Modern": "Modern" pieces by Franz Liszt, including Fantasy and Fugue on the Theme B-A-C-H, the Bagatelle sans tonalité, etc.
- J.S.BACH: Goldberg Variations (piano)
- J.S.BACH: The Well-Tempered Keyboard (piano) (integrale, 48 preludes and fugues in 3 CD)
- J.S.BACH: The Art of Fugue (on organ and harpsichord)
- J.S.BACH: The Musical Offering (on electronic instruments)
- "Shadowy Arcade" free improvisations on solo piano
On other labels:
- "Live at Salt Lake City": Recital, recorded live (1991)
- "TANGO, Best tangos by A. Piazzolla": personal arrangements for piano solo
- "Mehmet Okonsar Plays Gershwin" Complete works for the solo piano by Georges Gershwin and a personal transcription of the Rhapsody in Blue
With other artists:
- "T.R.T. Youth Choirs 20. Anniversary": Commissioned work by the T.R.T. (Turkish National Radio and Television) for a cappella choir;
- "T.R.T. Chamber Orchestra": J.S. Bach, concertos for keyboard in F min. and G min.
Adept of Free Music philosophy, Okonsar publishes all his recordings and writings as well as his compositions on the Internet under the GNU GPL or Creative Commons licenses.
The compositions by Okonşar were from the beginning exploring unusual ensembles in an avant-garde line. During the eighties atonal (free) Jazz specially by Cecil Taylor and the intricate voicings by Bill Evans had strong impact on the total serialism Okonşar always used. Other extra-serialist influences are Krzysztof Penderecki, Iannis Xenakis and György Ligeti.
The electronic works created in the fifties and early sixties by Ligeti, Karlheinz Stockhausen, Xenakis, Henri Pousseur and others created a new and previously unheard approach to orchestration. The sound possibilities of the classical orchestra started to be conceptualized by the composers in terms of "sound envelopes", "sound filters and formants. Okonşar followed a similar path in his orchestrations, in the nineties.
The music by Okonşar is extremely structuralist and calls for an analytical approach. This structuralism is presented in the finished score in a very detailed, complex and refined musical écriture.
- "Concertango" (2012) Concerto for piano and small orchestra, based on themes by Astor Piazzolla. Dedicated to Mr. Burak Tüzün. Première in Adana (Turkey) by the composer and the Cukurova State Symphony Orchestra, conducted by Mr. Burak Tüzün.
- "Hatikvah" a piano solo arrangement of the theme, released into the Public Domain by the composer, available at IMSLP.org.
- "Shir Ha Shirim" שיר השירים For soprano and grand orchestra (2010).
- "Tehillim" תהלים For solo vocal (male or female) and small orchestra (2010).
- "Kaleidoscopes" (2006–2009)
- N1. for Piano Première by the composer in Ankara
- N2. for Strings Chamber Orchestra, Marimba and Piano. Première conducted by Hakan Sensoy in Istanbul
- N3. for Viola and Piano. Première by Çetin Aydar (viola) and the compositer in Ankara
- "Percussion X" (2005) For three percussionists. Première in Ankara by he Trio SaNeNa.
- "Temples of Kyoto" (2004–2010) Three pieces for the piano,
- N1. "Kinkaku-ji" 金閣寺, The Temple of the Golden Pavillon, Première by the compositer in Tokyo (dedicated to the memory of Mrs. Yasuko Fukuda)
- N2. "Tetsugaku no Michi", Philosopher's Walk 哲学の道
- N3. "Ginkaku-ji" 銀閣寺, The Temple of the Silver Pavillon
- Ahmet Taner Kışlalı Anısına (Ahmet Taner Kışlalı In Memoriam) for viola solo (2004)
- "Two Seascapes" (2000) for mixte choir a cappella. Première conducted by Prof. Mustafa Apaydın, Ankara.
- "Rhythm Studies pour Piano Solo" series 2 (2000)
- "Rhythm Studies pour Piano Solo" series 1 (1999), inspired by the "Schillinger System of Musical Composition"
- "Oannés" & "Mr. Dunne" (1990) Two sketches for improvisation for one or several piano(s). Première by the compositer in Brussels.
- "Unknown" (1989) for Bass Clarinet and Percussion. Première in Brussels.
- "Mandel Fractal Studies" (1997) Five pieces for the Piano based on fractals.
- "Emulation" (1989) Five Pieces for the Piano. Première by the compositer in Istanbul.
- "Chameleon" (1987) Three Pieces for the Piano. Première by the compositer in Brussels.
- Biography & discography from Okonsar's official website
- Short Biography at "bach-cantatas.com"
- Short Biography (Turkish)
- The first level of the "High Education in Music" diploma the Brussels Royal Conservatory awarded at the time
- The second level diploma of the Brussels Conservatory, equivalent to the Masters in Art degree, given as a result of a competition-like public performance.
- Now: "de Singel Internationale Kunst Campus"
- Now named: Royal Flemish Philharmonic
- This is stated at his official website.