Jan Prokop made her West Coast opera debut with the Opera Eugene singing a "sympathetic and seductive portrayal" (Eugene Register-Guard) of the effervescent Musetta in La Boheme and has appeared throughout the country as Susanna in The Marriage of Figaro. She was the soprano soloist in performances of The Messiah at the National Cathedral in Washington, D.C. The Washington Post hailed these performances as "(bringing) to mind the great tradition of British oratorio singers with her dark lower register, warm vibrato and silvery high notes". The concert was later broadcast on National Public radio.

Following her appearance in the Bach Magnificat with Bach Society of St. Louis, the St. Louis Post-Dispatch called her "…a stylish singer, concerned as much with the communicative treatment of words as with rich sonority and shapely phrasing". Most recently she joined the Berliner Cappella Chor and Kammerorchester for their performance of the Marienvespers of 1610 by Monteverdi.

Equally at home on the musical theater stage, she has enjoyed successes as Johanna in Sweeney Todd, Gooch in Mame, Maria in The Sound of Music, Lizzie in 110 in the Shade, and as Camelot's Queen Guenevere. She has appeared with the Augusta Opera, the Opera Theatre of St. Louis, Kansas City's Starlight Theatre, St. Louis MUNY, and the Festival Lyrique de Belle Ile en Mer. Some highlights are A Little Night Music, Albert Herring, Bye, Bye, Birdie, My Fair Lady & Carnival. Jan's many operatic roles include Adele in Die Fledermaus, Anne Page in The Merry Wives of Windsor, Zerlina in Don Giovanni and Gilda in Rigoletto.

Jan is also a champion of 20th century music. In addition to performing the traditional oratorio repertoire of Brahms' Ein Deutsches Requiem and The Lord Nelson Mass of Haydn, she has been the soloist in Poulenc's Gloria, the Magnificats of Berio and Pärt, St. Luke Passion of Penderecki, Orff's Carmina Burana, and Britten's Les Illuminations.

A popular recitalist, she has performed numerous times in New York City, St. Louis, Washington D.C., Le Palais (France), Jerusalem, and Curitiba and Brasilia, Brazil. A highlight of her concretizing was a recital with Jan Gippo, principle piccolo with the St. Louis Symphony, that was broadcast live from the St. Louis Botanical Gardens. Her South American debut was as a recitalist in São Paolo in a concert that included Brasilian folksongs and selections from the Great American Songbook.