When the French armies entered Bonn, at the commencement of the revolutionary war, the Elector’s musical establishment was broken up, and the two cousins proceeded to Hamburgh, where they readily obtained engagements in the orchestra of the German Theatre. In 1795, they left Hamburgh, and, continuing their mutually beneficial compact, made journeyings together through several cities of Germany and Italy, establishing everywhere the reputation of being among the best violin and violoncello players of the day. Their duetts and concertante performances, in particular, had that perfect harmony of finish which the constant habit of studying and playing _together_ could perhaps alone bestow. The familiar interchange of ideas was likewise of advantage to them in the compositions which they produced, whether conjointly or separately. They may be styled, by no very forced parallel, the “Beaumont and Fletcher” of the musical world. In 1797, they returned to Hamburgh, where Andreas remained; while Bernard, two years afterwards, made a separate excursion through England and Spain, to Lisbon, and, returning to Hamburgh about 1803, obtained subsequently a situation in the Royal Chapel at Berlin. Andreas had, in the mean time, turned his attention more extensively towards composition, and produced works involving larger combinations, and full orchestral agency, such as it is not requisite here to specify. Both the cousins, moreover, are _best_ known as voluminous, and at one time highly popular, composers for their _own_ particular instruments. Their chief instrumental works, as an English critic has remarked, will always be heard with pleasure, although without the excitement which attends Beethoven, or the deep admiration which waits upon Mozart. Of these works it may suffice here to enumerate:— Four Concertos for the violin—two Quintetts—twenty-four Quartetts (comprised in eight sets)—a Quartett for the pianoforte and stringed instruments—nine Duetts—and a set of three Studios, or Sonatas for the violin—by _Andreas Romberg_. A set of three Quartetts—four single Quartetts—a Trio for violin, tenor, and violoncello obligato, in F—six Concertos, and several Concertantes and Airs with Variations, for the violoncello—two Quartetts for pianoforte and stringed instruments—by _Bernard Romberg_.