Valentinas Adamkevičius  graduated in 1950  from the Lithuanian Conservatory. His teachers were Aleksandras Kačanauskas and Kipras Petrauskas. Since 1956, 
he taught singing at the  Lithuanian Conservatory himself, and 1964–1966, he was head of the singing department. 
 
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| Lithuanian Conservatory, Vilnius | 
1948–1950 and from 1954, he was a member of the Lithuanian National Opera.  He also sang  in Leningrad at the Kirov. 
Adamkevičius sang lyrical, and  dramatic parts  in operas, cantatas and oratorios. 
 He prepared
 some 60 roles. 
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| Lithuanian National Opera, Vilnius | 
He toured India. He also interpreted a series of rare complex works written by Julie Kachin, Claude Debussy, 
 Johannes Brahms, Franz Schubert, Ottorino Respighi.  
 His repertory included:
 
Liutauras in Jurgis Karnavičius' Gražina; 
Don José; Rodolfo;  Vladimir Igorevich; Don Carlo; Radamès; Otello; Danyla and  Vienuolis in  Pilėnai by Vytautas Klova.