C.P.E. BACH. Harpsichord Concertos: E major, Wq14 ; G major, Wq43 No. 5.

MOZART. Harpsichord Concerto in D major after J. C. Bach, K107 No. 1. Trevor Pinnock (harpsichord), English Concert directed by Trevor Pin- nock. CRD CRD1011 (f2•80). CRD Ltd., 97-9 Dean Street, London Wl.

Now that so many records are made "on authentic instruments", we need to have a more precise definition of 'authentic'. Is a violin authentic in eighteenth-century music simply because it was made in the eighteenth century (or before) ? It will probably have been substantially rebuilt since then, like most early fiddles in use today; it may be played with modern wire strings; the bow may be much later and altogether the wrong shape. It may be contemporaneous with the music, but built hundreds of miles away from where the music was composed and belonging to a different performing tradition. It may have been built in 1975 but carefully modelled after an early instrument.

On this disc, says the sleeve-note, the music is played "on authentic instruments". There are no details about the string or wind instruments, but the harpsichord dates from 1972—though modelled on a German instrument of 1745. I have no complaints about the quality of sound, which seems to me well attuned to the music: the harpsichord is bright and sweet, and the strings are warm and clear and are played with little or no vibrato. The performances themselves are stylish and efficient. This ensemble has given a number of good concerts in London and their playing here is in the same manner as those I have heard: accurate and musical, tasteful, just lacking that dash of fancy or imagination or brilliance to make it really out of the ordinary. Trevor Pinnock's fingerwork is always neat and crisp in the ornamental writing and the passage-work. The E major Concerto by C. P. E. Bach has an expansive first movement, rather more strongly organized and more continous than much of his music, if less bold; the slow movement is a sombre-toned Adagio with muted strings in E minor, full of impassioned chromatics, and the finale is lively and relatively straightforward. This dates from 1760; the G major of 1772 is a shorter work, its movements continous (as Carl Philipp came to prefer)—there is a short Adagio for strings alone, then a brilliant Presto led off by the soloist, followed by a characteristically expressive Adagio and a cheerful, light-textured Allegro.

The Mozart work is one of his three concertos after sonatas by J. C. Bach written about 1771 (not around 1765, as the sleeve-note relying on long outdated sources, says; the original sonatas probably weren't composed by then): Mozart did little more than add ritornellos and accompaniments to the originals, and later provided cadenzas, which are duly played here. These pieces perhaps sound slightly better on the fortepiano than the harpsichord. But this is an agreeable disc with stylish performances that cannot fail to give pleasure. S.S.