At age 7 he starts playing violin, piano, mandolin and obtains at the age of 14, at the Music Academy, the Government Medals for violin, piano, chamber music and sol-fa.
He becomes then a student at the Music Royal Academy of Liege in the violin class of the Rumanian virtuosos Lola BOBESCO and Richard PIETA. When he is 17, he wins his first prizes and then improves with two violinists, Thadé GEISLER-WYGANOWSKI (PL) and Jean DONNAY (B) with whom he creates an Ancient Music Quartet, "Les Cordes Mosanes".
During that period, he is also a member of the "Beaux Arts Orchestra" of Brussels as well as the Chamber Orchestra of Lausanne. In the early 70's, with friends from secondary school and from the Academy, he creates the Folk Music Group "Triskan" (Thierry MAQUET, Jean-François DUMONT, Albert FRERE, Jean-Paul LEBENS, Patrick WILLEM) which had an enormous success at that time.
During the 70's, he creates various Groups of Jazz, Rock Jazz and Electronic Music with Henry POUSSEUR, Jean-Marie BILLY, Philippe BOESMANS, and his brother Patrick WILLEM who was then bassist and contrabassist of Jacques PELZER and Chet BAKER.
In 1978, he takes off to the United States and Los Angeles is where he discovers with Jean-Luc PONTY the creative opportunities offered by the electric violin. At that time, like Jean-Luc, Daniel buys his first electric violins from the BARCUS-BERRY company in Los Angeles. He will remain loyal to this company that he promotes and represents, saying "Amongst all the electro-acoustic violins and all the microphones for violins that I could test so far, the piezo crystal system of BARCUS-BERRY is the only one that allows such a real quick response to the stroke of the bow, as well as precise and immediate clearness of sound. As far as I am concerned this is the best system that I ever had the occasion to use".
It is still in California that he is invited by Stephane GRAPPELLI at the Royce Hall of UCLA.
In 1980, he plays with the american jazz drummer Art BLAKEY, at the famous Village Vanguard in New York.
Back from the USA, he creates again groups of Jazz-Rock, Fusion, Latin (Baba Trio, Baba Cool, etc...) with his brother Patrick as bassist, Jean-Pierre FROIDEBISE, Stephane MARTINI, Marc-Henri CYKIERT at the guitar, Jean-Marie BILLY, Denis POUSSEUR at the piano, Yves BAIBAY, Philippe DEMANY and Pierre ADAM at the drums, Milou STRUVAY at the trumpet, Jacques PELZER and Stephane HOUBEN at the saxophone. It is important stressing that Daniel WILLEM was at that time, like Jean-Luc PONTY was in France, the first belgian electric violinist playing Jazz and Jazz-Rock, with the result that he showed the way to several young belgian violin players such as Yves TEICHER, Jean-Pierre CATOUL, Cecile BROCHE, Alexandre TRIPODI, Françoise DERISSEN, etc..
Later on, he works in the United States and in Canada, in Brussels, Paris and London as an arranger, studio musician, sound engineer, and he contributes to numerous successes of the 80's (Marvin GAYE, Paul YOUNG, Allison MOYET, etc...) In 1985, he arranges, plays and co-produces Viktor LAZLO's album "She" that became an international success, with the single "Pleurer des Rivières" that happened to be one of the biggest hits of the 80's as it remained for 13 weeks in the Top 50.
In 1988, in Dublin, he conducts the Eurovision Orchestra for the Belgian singer Joseph REYNAERTS for whom he composed and arranged the song "Laisser briller le soleil" that obtained a platinium record in Scandinavia and that was also sung by Johnny LOGAN.
Then he leaves again for the United States and Canada and performs in a series of concerts and recordings with american musicians in Los Angeles, San Francisco, New York, Montreal, Quebec.
In 1990, as a singer, he signs an artist contract with CBS as well as an editorial contract with EMI, for the song "Seul à traîner" (text from Marc DIXON, and a clip co-produced by Sony and M6, and created by the clip creation team of J.J. GOLDMAN). This song ends up in the Top 50 and in the Top 10 of the titles programmed the more often in France.
Since the beginning of his carreer, Daniel WILLEM has made for himself but also for several artists an impressive number of concerts and studio sessions over the world, playing as violonist, mandolinist, keyboard player, organist, guitarist, composer, arranger, sound engineer, creator and producer. He obtained with some of these artists numerous platinium and gold records: Stéphane GRAPPELLI (FR), Chet BAKER (USA), Don ''SUGARCANE'' HARRIS (USA), Art BLAKEY (USA), Al et Stella LEVITT (USA), Kermit DRISCOLL (USA), Bill FRISELL (USA), John THOMAS (USA), Toots THIELEMANS (B), Tucker ZIMMERMAN (USA),Tony TRISCHKA (USA), Marvin GAYE (USA), Charles SHILLING (B), Jennifer McRAE (CA), David ''HAWK'' WOLINSKI (USA), Rod GAMMONS (UK), Marcel AZZOLA (FR), Jean-Pierre FROIDEBISE (B), Quentin LIEGEOIS (B), Pascal MOHY (B), Eric LEGNINI (B), Bruno CASTELLUCI (B), Pierre VAN DORMAEL (B), Francis CABREL (FR), Mimi VERDERAME (B), Kevin MULLIGAN (USA), Guy REBOUL (FR), Steve HOUBEN (B), Robert LAFONT (FR), Phil ABRAHAM (B), Jean-Paul CHARLAP (FR), Jacques PELZER (B), Ivan PADUART (B), Ralph BENATAR (USA), Stéphane GALLANT (B), Léon HUMBLET (B), Hubert SCHOONBROODT (B), Michel HATZIGEORGIOU (B), SOULSISTER (B), Bill DERAIME (FR), MAURANE (B), David KOVEN (FR), Sam GERSTMANS (B), Le ROSENBERG TRIO (NL), Pierre THEUNIS (B), INIT (B), ELMORE D (B), Milou STRUVAY (B), Toon VAN DIONANT (B), Jean-Marie BILLY (B), Jan DEBRUYN (NL), Nicolas FIZMAN (B), Marc LAVOINE (FR), Plastic BERTRAND (B), Lou DEPRIJCK (B), SMOKY MOKES (B), Jacques STOTZEM (B), Guy CABAY (B), Christiane STEFANSKI (B), Pierre MARTIN (B), Jacques-Yvan DUCHESNE (B), André KLENES (B), André CHARLIER (B), Yves BAIBAY (B), Benoît VANDERSTRAETEN (B), Serge GHAZARIAN (B), ODIEU (B), Marc DESCAMPS (B), Yves TEICHER (B), Evert VERHEES (B), Viktor LAZLO (B), Ginette RENO (CA), Fabrizio CASSOL (B), Alan STIVELL (FR), BELGAZOU (CA), Anne FROIDEBISE (B), Alec & Benoît MANSION (B), Marc MORGAN (B), René STOCK (B), Silvio PECCI (B), Stéphane MARTINI (B), Christian MORIN (FR), Daniel FALKE (FR), René STOCK (B), Juliette GRECO (FR), François RAUBER (FR), Gérard JOUANNEST (FR), Luc RIGAUX (B), Patrick SAMOY (B), Joseph REYNAERTS (B), Philippe LAUMONT (B), Nathalie LAVIGNE (B), Phil CORTHOUTS (B), CLOUSEAU (B), Will TURA (B), Claude BARZOTTI (B), Sandra KIM (B), Mario GUCCIO (B), Santo BARRACATO (B), Philippe LAFONTAINE (B), Pierre RAPSAT (B), etc…
With Jean-Pierre FROIDEBISE, he created a "Tribute Band", the "Tambourine Men" group that recalls the career of Bob DYLAN.
He gives lessons and trainings within the scope of the education program proposed by the "Jeunesses Musicales " of Liège. Daniel WILLEM acts also as an endorser for american companies such as BARCUS-BERRY (violins, microphones, preamplifiers) since 1978, MUSICORP (instruments, accessories, musical and sound equipments), EASTMAN (mandolins, guitars, violins, accessories), as well as for the German company PIRASTRO (strings).
Since the early 70's, he holds his own recording studio which gives him the opportunity to explore his different musical universes. Multi-instrumentist, he creates his recordings by his own (keyboards, rythmics, etc..), that his musicians will join later on depending on the atmosphere corresponding to his compositions. This explains the particular tone of his creations, and more especially the recordings that he created with his son Thomas WILLEM and Luc RIGAUX.
His musical universe is a travel through Jazz, World Music, Classical Music, a colourful and personal musical world, made of lights and shades as well as harmonic atmospheres.
Daniel WILLEM is presently one of the more creative violinists thanks to his impressionist and melodic compositions, often inspired by DEBUSSY, RAVEL, FAURE, LEKEU, etc..., his stroke of the bow that one immediately recognizes, expressive and sensitive, rythmic and electric, closer to Jean-Luc PONTY than to the classical Swing style of Stephane GRAPPELLI.