JOHANN CHRISTIAN BACH may not have been the greatest of Sebastian's sons - that designation is usually reserved for his older brother Carl Philipp Emanuel - but no one in the family wrote more engaging music than this "English Bach," who made such an impression on the eight-year-old Mozart when they met in London. The six litle sinfonias that constitute Christian's Op. 18 (his London Op. 18, that is - a different set of symphonies was published in Amsterdam under the same opus number) are surely among the most attractive works of their kind, and it is a wonder, in this "Age of Complete," that no one has got round to giving us an "integral" recording of them.

On a new London release (CS-6988), Karl Muenchinger and his Stuttgart Chamber Orchestra offer all three of the even-numbered components of Op. 18 with the charming Don Quichotte Suite of Telemann. This appears to be a disc premiere for Op. 18, Nov. 6, in D (the only four-movement work in the collection), and it is the only version of the famous Op. 18, No. 2, in B-flat (the overture to Christian's opera Lucio Sillo available now. It looks like a winner, but turns out to be perhaps the most disappointing record these fine musicians have yet made.

The playing is gruff and heavy-handed, the pacing inflexibly determined, the phrasing square and anything but suave. Even the annotation is conspicuously undistinguished, not only missing the point of the Telemann piece completely, but suggesting that Christian's sinfonias, written about 1780, "must surely have echoed in Mozart's head as he penned his Symphony No. 29 in A" - in 1774! No reference is made to the oboe solo in the slow movement of the B-flat Sinfonia, one of the most celebrated examples of its king. Etc., etc.

Anyone who has heard the elegant performance of the B-flat under Mogens Woeldike, on the same London label, or the similarly stylish one of Op. 18, No. 4, in D under Paul Sacher which appeared here on two or three labels before it last disappeared, knows how this music ought to sound, and it would be my hope that some record producer would be imaginative enough to get hold of Woeldike, who is still vigorously active in Copenhagen, and do the entire Op. 18 set with him. The Muenchinger package, unfortunately, cannot be recommended, even as a stopgap.

All the sensitivity and warmth Muehchinger fails to muster on behalf of J.C. Bach and G.P. Telemann with his own ensemble are gloriously in evidence in the same conductor's recording of Schubert's music for Rosamunde with the Vienna Philharmonic (London OS-26444). This is the complete sequence, with the Zauberharfe Overture that has come to be known as the Rosemunde Overture. It would have been nice to have the Alfonso und Estrella Overture, which was actually played for the first production of Rosamunde, but everything here is done so beautifully that this thought does not occur in the nature of a complaint. Muenchinger's superb feeling for this music is reflected not only in his affectionate shaping of phrases and well-chosen tempos, but in his judgement on which repeats should be taken and which omitted. Rohangiz Yachmi, a contralto from whom we'll surely hear again, is most effective in the Romanze, and the Vienna State Opera Chorus is at its best in the three choral numbers. An utterly enchanting recording.