He first attracted public attention by his performance, on 5 February 1842, of Damon on the production of Acis and Galatea (Handel) under William Macready at Drury Lane.
In John Edmund Cox's Musical Recollections, he is identified as "the only person worth listening to, in spite of the limited powers of his organ".
From that time until the close of John Medex Maddox's management in 1850, Allen was continually engaged at the Princess's, where, owing to its small size, he was heard to advantage.
In the early part of 1846 he was engaged at Drury Lane, where he played Basilius on 3 February in George Alexander Macfarren's production of An Adventure of Don Quixote.
À propos of this part, Henry Chorley, in the Athenæum, considered him, both as singer and actor, as the most complete artist on the English operatic stage.