For the next nine years, he starred in a series of hit Broadway musicals including Her Soldier Boy, Maytime, Naughty Marietta, and Apple Blossoms (with Fred and Adele Astaire).

Thomas sang in a concert performance of the Market Scene from Rimsky-Korsakov's opera Sadko at Manhattan's Carnegie Hall in December 1924.

During the 1922-28 period, he spent part of each year in Europe, polishing his singing technique and appearing under contract at La Monnaie opera house in Brussels for the seasons of 1925-27.

Even more importantly, he appeared with the famous Russian bass Feodor Chaliapin in productions of Faust at the Royal Opera House, Covent Garden, London, in July 1928.

He continued to give recitals in the United States during this period and, in 1923, acted in a silent film, Under the Red Robe, directed by Alan Crosland.

In 1938, he helped Edwin Lester launch the Los Angeles Civic Light Opera, appearing in the company's very first production in Blossom Time.

This work was derived from a Viennese operetta Das Dreimäderlhaus, with music arranged from that of Schubert and adapted for American audiences by Dorothy Donnelly and Sigmund Romberg.

He probably reached his widest audience during this period, although his practice of performing songs exclusively in English has perhaps left him less well-remembered by today's musical "purists" than he should be.

Nevertheless, many songs tailored for him to sing have gone on to become standards, such as the version of "The Lord's Prayer" by Albert Hay Malotte and the arrangement of "Home on the Range" by David W. Guion.

[4][5] John Charles Thomas left a large pool of audio recordings, many of which sold extremely well in their day and have been transferred in recent times to compact disc.

His operatic voice is probably best appreciated in commercial offerings such as "Nemico della patria" from Andrea Chénier, and "C’en est fait… Salomé demande" from Hérodiade.

His early recordings display a darker tonal hue, and the voice is stiffer, as though he were imitating the stentorian Italian baritone of a previous generation, Titta Ruffo.