THE CONDUCTING BUG BITES many established instrumentalists, some singers as well, and especially, it would seem, young pianist. Vladimir Ashkenazy is one who has recently taken up the baton. His latest recording as a conductor is a delightful one, with Cristina Ortiz as soloist and the New Philharmonia the orchestra, of Villa-Lobos' two most attractive works for piano and orchestra, Momoprecoce and the Bachianas brasileiras No. 3 (Angel S-37439). Ashkenazy is also on records as conductor of the Tchaikovsky Violin Concerto (with Boris Belkin) and some works of Prokofiev without soloist, but so far has made no recordings as both pianist and conductor.

Daniel Barenhoim and Phillippe Entremont are among those who have done that, both of them in Mozart concertos, the most favored vehicles for this sort of thing. Barenhoim, in fact, like the late Geza Anda, has recorded all the Mozart concertos in the dual role, though not all of those recordings have been released in this country. The latest to enter the conducting-from-the-keyboard discography, again with Mozart concertos, is Murray Perahia, surely one of the two or three most interesting pianists of his generation. He is not, however, one of the most accomplished conductors.

Perahia operates at full strength in his solo recordings, such as the recent Columbia disc of Schumann's Symphonic Etudes and Papillons (M 34539) and in his one recording to date as concerto soloist with another conductor (the stunning disc of the two Mendelssohn concertos, Neville Marriner conducting, M 33207). His earlier pair of Mozart concertos with the English Chamber orchestra (Nos. 14 in E-flat, K.449, and 24 in C minor, K. 491. on M 34219) showed some interesting ideas about the works, as well as fine playing, but was handicapped by the impression that he was not only unable to do justice to the orchestral role but was perhaps even kept from full realization of his pianistic one in the attempt.

His new Mozart disc, with the same orchestra (Concertos Nos. 9 in E-flat, K. 271, and 21 in C major, K. 467, M 34562), is even more attractive pianistically, and perhaps for that very reason more frustrating for its similar shortcomings. Everywhere the piano part seems marvelously freshened, yielding new depths and new delights without self-consciousness on Perahia's part, but, particularly in the well-loved K. 467, one misses a similarly attentive, imaginative and skilful handling of the orchestral part, which is no mere "accompaniment" in this work. So outstanding a pianist deserves a finer conducting partner, and Columbia should see that he has one in future undertakings.

While the new Perahia disc is treasurable for the solo playing, the performance of K. 467 on a recent Musical Heritage Society releae is more completely satisfying because the splendid playing of Maria-Joao Pires is fully and brilliantly matched by orchestral contribution (Gulbenkian Foundation Chamber Orchestra) under the thoroughly professional Theodor Gushlbauer. It is a perfectly lovely realization of the concerto, and the imaginative programming on side two brings us similarly attractive performances of Mozart's two concert rondos (K. 382 in D, K. 386 in A), separated by the solo Rondo in A minor, K. 511.

Both sides of the Pires/Guschlbauer disc (MHS 3737) are exceptionally satisfying. This is music-making on a high level indeed, and with all elements judiciously balanced - including the fine sound (by Erato). Several musicians, by the way, had a hand in the restoration of K. 386; Pires plays the now more-or-less standrd edition of Paul Badura-Skoda and Charles Mackerras, with a cadenza by none other than George Szell. To their discredit, neither MHS nor Columbia identifies the cadenzas in the concerto performances - a dismayingly widespread oversight these days, in concert programs as well as on records.