Cool breezes from Mostly Mozart and City Opera. Guest soloists and new `Barber' enliven summer music season

SUMMER has become almost as busy a musical season here as winter. And, in the current heat wave, air-conditioned concert halls are more than ever hospitable havens from the elements. The two institutions contributing the most to the concert scene are both at Lincoln Center - the Mostly Mozart Festival at Avery Fisher Hall, and the New York City Opera at the New York State Theater.

The City Opera tends to offer lighter fare in the summer, and it should come as no surprise that the company would choose Rossini's ``The Barber of Seville'' for its second new production of the season. Mostly Mozart devotes much of its energies to the composer who gives the festival its name, but the programming has, under music director Gerard Schwarz, widened to include the Bachs, Prokofiev, and composers in between.

It's somewhat fashionable to write off Mostly Mozart as an unchallenging festival that stresses non-provocative programming and performances. But the event clearly fills a need, even if judged merely by the numbers of ``sold out'' signs over the years. And Mostly Mozart offers an interesting array of soloists (two per program) and conductors.

A recent concert presented flutist Jean-Pierre Rampal and pianist Stephen Hough in a Schwarz-led evening of Prokofiev, Mozart, and Hummel. In an earlier concert, I caught up with Sir David Willcocks offering an all-Mozart choral evening with the Westminster Choir.

The highlight of the two programs was Mr. Hough's effortlessly brilliant account of the Hummel Piano Concerto in A minor, Op. 85 - a work presented with high professionalism throughout and an occasional glimmer of true musical accomplishment. The piano part is virtuosic in the extreme and richly operatic in gesture. Hough was up to the technical demands, and he intuitively understands the musical and exhibitional aspects of the piece. The concert proved once again that he is perhaps the most all-around-talented young pianist to appear on the scene in quite some time.

Rampal's playing of the Mozart was problematical in just about every aspect, and Schwarz's interpretations of the Prokofiev Classical Symphony and Mozart's 29th Symphony seemed at odds with Mozart's intentions, since both performances tended to lack humor and sparkle.

Willcocks brought a seasoned sureness to his choral program, and, while there were no musical revelations, the performances were bedroom-slipper comfortable in their traditionalism and confidence. This was particularly true of the C major Mass (K. 167) and the peppy account of the Requiem (K. 626). As if to prove that Willcocks was not in a provocative mood, he used the familiar S"ussmayer edition of Mozart's unfinished work, rather than attempt to come to terms with another edition using only the music Mozart is known to have written.

A similar decision to emphasize the comfortable and familiar is at the root of the City Opera's new look at Rossini's ``Barber.'' This opera has not been well served of late in New York. City Opera's last production bombed with particular force, and the Metropolitan Opera's production was quite dull and tedious, even though considerably more money was spent on its endeavor than on the two City Opera productions together.

The new Lotfi Mansouri production limps along with little style or humor, and with hardly an attempt to delve beneath the standard caricatures. Desmond Heeley's picture-post-card-pretty sets and costumes tend to abet the feeling of superficiality.

The cast is good, and in a few cases more than good. I particularly like Harry Dworchak's handsomely sung, sly, and wickedly amusing Don Basilio, and Robert Orth's energetic and robustly sung Figaro. (If only they would change Orth's dreadful wig and makeup!) Jan Opalach makes a serviceable, if stolid, Bartolo, and Gran Wilson a wan-voiced, insecure Almaviva.

In true old-fashioned style, a coloratura soprano, rather than a mezzo, is cast as Rosina. Erie Mills knows her way around this sort of part, and she holds the stage with confidence and ease. Only some passing moments of faulty intonation intruded on her otherwise delightful opening-night performance.

Music director Sergiu Comissiona - who recently announced his resignation, effective the end of this year - stressed balances and steady tempos over froth or pliancy. Everyone could go home happy in the knowledge that, while ``Barber'' did not exactly come memorably to life, a good time was had by most.

Thor Eckert is music critic for The Christian Science Monitor.