Improvisation also flourished in concerts and soirées; and playing and composing, which in improvisation form a true union, can only with difficulty be severed in an age of creative virtuosos. Kalkbrenner composed while playing, and played while composing, so that no one could tell the difference between the two; and Czerny used to invent the necessary étude in the midst of the lesson. Thus it happened--a state of things unparalleled to-day--that the beloved duet-playing could be combined with the equally beloved improvisation--mutually contradictory as they appear. Moscheles speaks of an improvised duet with Mendelssohn. The latter played in the bass some English songs in ballad-style; the former interwove in the treble the scherzo of his friend’s A minor symphony. Slight as was the advance yet made in division of labour between player and composer, there was equally little comprehensive division between the species of music. We do not hear of chamber-music evenings, pianoforte evenings, orchestral concerts. All was mingled in one; and chamber-music finds the same audience as the symphony. A piano-recital without orchestra was a rarity; and the concerto-form is almost _de règle_ in all the greater performances. This is seen in the compositions of this period, which, as a rule, so far as they are specially adapted to public performance, were written for orchestral accompaniment. By their side were editions for private use, including the important orchestral portions. This concerto-piece could not greatly or permanently aid in the advance of a delicate or intimate piano-music. Through the rarity of special piano recitals it was not so easy to get pianos when they were wanted. In Frankfort there lived a well-known old lady who had absolutely the only piano store in the city. People had to praise her playing, to blow the trumpet of advertisement for her wares (they were Streicher’s), to court her and cringe to her in order to get an instrument for a concert.[122]