Boston's Concert Opera

Boston has its own sort of Queler operation, directed by David Stockton under the name Boston Concert Opera Orchestra. Later in its season, Stockton will offer Verdi's ''Il Battaglia di Legnano,'' but recently, Boito's masterwork ''Mefistofele'' was on the boards. It is an ambitious work for the typically young cast Stockton assembles. It is also a work that needs a fully staged production to cover up some of the more than incidental longueurs that are interspersed between beautiful things.

John Cheek was singing the title role - he has sung the Prologue for Telarc Records - and his lightweight bass was seriously taxed. One can only conclude that, for the well-being of his instrument, he should not be performing this role even in so small a house as Jordan Hall.

Tonio di Paolo revealed a vibrant tenor, still in the formulative stages in its consistency, style, and stamina. But the ring to his top notes is rare in the tenor world today - so rare that one fears he will be ruthlessly exploited before he has matured vocally. Roberta Laws proved vivid histrionically, while distressingly uneven vocally. Elizabeth Knighton was the dutiful Elena. The combined Masterworks Chorale and COO Chorus sang robustly. Stockton led the evening with sureness and grand touches of dramatic sweep.