While studying at the gymnasium, he played in the orchestra, sang in choirs and accompanied them. He studied music privately: music theory and harmony, singing, conducting, playing the piano and playing the trumpet. His first teachers were F. Strolia, M. Memėnaitė, V. Gutauskas and others. In 1987, he graduated from the Illinois Institute of Technology with a master's degree.
From 1982 to 1992, he was a music and singing teacher at the K. Donelaitis Higher Lithuanian School in Chicago.Since 1995, director of the children's choir of the Blessed Jurgis Matulaitis mission in the Chicago area. The choir sings in the church, participates in concerts.Since 1988, D. Polikaitis has been the artistic director and conductor of the Chicago Lithuanian art ensemble "Dainava" (about 60 participants). The collective organizes concerts and musical performances, participates in song festivals and other national events. In 1995, "Dainava" celebrated the 50th anniversary of its creative childhood with a concert.
in 1998 January 18 in the religious music concert, among other works, the ensemble performed "Requiem" by the English composer J. Rutter. The "Dainavas" ensemble has performed in Washington, Cleveland, Detroit, Toronto, Grand Rapids, participated in the 1990 Lithuanian National Song Festival, 1994 I and 1998 II World Lithuanian Song Festivals in Kaunas and Vilnius
D. Polikaitis was the conductor of the 1991 7th US-Canada Lithuanian Song Festival in Chicago, 1992 9th National Dance Festival of Lithuanian Diaspora in Rosemont Horison, Illinois, 1994 I and 1998 II World Lithuanian Song Festivals in Kaunas and Vilnius. He is a member of the board of the Lithuanian Musicians Union of North America - vice-chairman and a member of the American Choirmasters Union. In 1984-1989 he performed as a singer in Chicago, Detroit, Cleveland, New York, Toronto, Los Angeles, in 1989 he participated in the Rock March in Lithuania - he performed in Kaunas, Klaipėda, Mažeikiai, Šiauliai, Panevėžys and Vilnius. Appears also as a composer. Creates popular songs, arranges folk dances for brass band. Released several records of his works. In 1993, he sang his song "Sveikas, Dievo Piligrime" on the occasion of a meeting of Lithuanian youth with Pope John Paul II in Kaunas. The entire Polikaičiai family is devoted to music: Audrius – accordionist, teacher, choirmaster of the "Dainava" ensemble, Rimas – pianist and accordionist, Rima – flutist, teacher, Vida – singer (soprano).
