She debuted with the New York Philharmonic under Artur Rodziński on December 14, 1941, performing the Sibelius Violin Concerto, with critical success.
Glenn and List were strongly interested in offbeat, rarely performed, and contemporary music, including the double concertos of Giovanni Battista Viotti and Anis Fuleihan, and the Duo Sonata by Franz Liszt, which they rediscovered.
Her last concert tour, in 1981, was to the People's Republic of China, where, in addition to performances, she gave master classes at the Peking and Shanghai conservatories.
Her playing had “an ingratiating lyric quality and a communicative charm, though there was a core of strength and determination that belied her youthful appearance.
Her tone was sweet and pure...; her technique was secure in a vast repertory.”[13][14][15] Miss Glenn’s violin was the Dragonetti-Walton Guarneri "del Gesù", 1742.