After high school, in September 1946, Evans attended Southeastern Louisiana University on a flute scholarship. He studied classical piano interpretation with Louis P. Kohnop, John Venettozzi, and Ronald Stetzel. A key part in Evans' development was Gretchen Magee, whose methods of teaching left an important print in his composition style. Soon, Bill would compose his first tune. Around his third year in college, Evans composed his first known tune, "Very Early". He was a founding member of SLU's Delta Omega Chapter of Phi Mu Alpha Sinfonia, played quarterback for the fraternity's football team, and was part of the college band. In 1950, he performed Beethoven's Piano Concerto No.3 for his senior recital, graduating with a Bachelor of Music degree, majoring in piano, and Bachelor's in Music Education. Evans regarded the last three years in college as the happiest in his life. During college, Evans met guitarist Mundell Lowe, and after graduating, they formed a trio with bassist Red Mitchell. The three relocated to New York City. However, their inability to attract bookings prompted them to leave for Calumet City, Illinois. In July 1950, Evans joined Herbie Fields's band, based in Chicago. During the summer, the band did a three-month tour backing Billie Holiday, including East Coast appearances at Harlem's Apollo Theater and shows in Philadelphia, Baltimore, and Washington, D.C. The band included trumpeter Jimmy Nottingham, trombonist Frank Rosolino and bassist Jim Aton. Upon its return to Chicago, Evans and Aton worked as a duo in clubs, often backing singer Lurlean Hunter. Shortly thereafter, Evans received his draft notice and entered the U.S. Army. During his three-year (1951-54) stay in the army, Evans played flute, piccolo, and piano in the Fifth U.S. Army Band at Fort Sheridan. He also hosted a jazz program on the camp radio station and occasionally performed in Chicago clubs, where he met singer Lucy Reed, with whom he became friends and would later record. He also met singer and bassist Bill Scott and Chicago jazz pianist Sam Distefano (his bunkmate in their platoon), both of whom became Evans' close friends. Evans' stay in the army was traumatic, and he had nightmares for years. As people criticized his musical conceptions and playing, he lost his confidence for the first time. Around 1953 Evans composed his most well known tune, "Waltz for Debby", for his young niece. During this period, in which Evans was met with universal acclaim, he began using recreational drugs, occasionally smoking marijuana. Evans was discharged from the Army in January 1954, and entered a period of seclusion, triggered by the harsh criticism he had received. He took a sabbatical year and went to live with his parents, where he set up a studio, acquired a grand piano and worked on his technique. The self-critical Evans believed he lacked the natural fluidity of other musicians. He visited his brother Harry, now in Baton Rouge, Louisiana, recently married and working as a conservatory teacher. CANNOTANSWER

Answer this question "When did he enlist in the army?" by extracting the answer from the text above.

Shortly thereafter, Evans received his draft notice and entered the U.S. Army.