The Arnes returned to London in 1777, and Michael was engaged as composer at Covent Garden for several seasons. In 1781 he was notably hired to provide a harpsichord accompaniment for "Eidophusikon", a display of moving pictures. In 1784–1785 he worked at the Haymarket Theatre as the director and conductor of the Lenten Oratorios. Upon his father's death in 1778, Michael inherited the majority of his father's assets, which included a number of unpublished manuscripts. Included among these were several organ concertos written in 1750s, and in 1784 Michael announced his intention to publish them. However, Michael died in poverty without having done so, leaving his wife destitute. The organ concertos were preserved and later published in 1787 by John Groombridge.