Together the two were the "Sweethearts of the Air", a radio show that ran for 16 years from 1923-1939, on NBC affiliate WJZ in New York where Breen played ukulele and DeRose accompanying her on the piano.

[2][4] Like so many performers during the era, Breen was a big fan of the instruments created by the C. F. Martin & Company and used a variety of their products, including a couple of custom inlaid models.

[13] In the refusal the representative told her that the ukulele was considered a "fun toy which isn't allowed in orchestras, and anyone can make a noise on it in a matter of days ... it was simply a novelty contraption...".

They refused for many years, but eventually, under her constant pressure with the support of such notable players as Cliff Edwards and Arthur Godfrey, the individual chapters relented.

[15] The Progressive Musical Instrument Corporation (P'MiCo) was a distributor that included the May Singhi Breen autographed model banjo uke in their line in the 1940s.

[18] On December 8, 1929 — seventeen months after her ex-husband was killed in Battery Park[17] — May married composer Peter DeRose (1900–1953), a man nine years younger, in Manhattan.

[19] Her daughter, Rita Lherie Breen (maiden; 1914–2007), married a 1932 West Point graduate, Byram Arnold Bunch (1907–1981) on October 29, 1933, in Manhattan.