Whatever has been going on behind the scenes at Scotland's most perennially dysfunctional national company, it has usually managed to deliver on stage, with the quality of its output being its ultimate defence.

There can have been few members of last week's first-night audience who were unaware that Scottish Opera has recently managed to lose its latest music director before he had conducted a bar of music in public, so it could have done with a triumphant version of one of Mozart's undisputed masterpieces now.

General director Alex Reedijk must have hoped that the dependable team of director Sir Thomas Allen and designer Simon Higlett would deliver just that.

Sad to say, with this Giovanni, the title role played with fine swagger by South African baritone Jacques Imbrailo, Allen's development from acclaimed performer to respected director, which the company has nurtured, appears to have stumbled.

There are layers of ambiguity in Lorenzo Da Ponte's libretto and Mozart's score that make it the most fascinating take on the tale of Don Juan, and while Allen's production is narratively as direct and clear as it can be, this new co-production with Boston Lyric Opera is disappointingly domestic in its vision and consistently grey in its staging.

Although the set is far from small - and the noisy hydraulics that accompanied the music on the opening night suggest it has its expensive technical components too - it suggests that this Casanova's shenanigans are within a small community, whatever the famous "catalogue" aria sung by his servant Leporello (Peter Kalman) suggests to the contrary.

For most opera lovers that might be a minor matter. The important thing about Don Giovanni is the music, but in that department the deficiencies on opening night were even more obvious. Under Italian conductor Speranza Scappucci, making her Scottish Opera debut, there were problems of balance and intonation everywhere: between different instrumental sections in the pit, between the orchestra and the stage, and - most damagingly of all - within the vocal ensembles that are the glory of the score.

Part of that may have been down to the absence of an indisposed Susan Gritton, who was due to make her Scottish Opera debut as Donna Anna but was replaced by youthful Australian Anita Watson, who emerges with credit, but although all the principles had their moments, when they come together at climatic plot points they failed to soar. That was also true of some of the individual arias, with Ed Lyon's nicely judged ineffectual prig of a Don Ottavio emerging with the honours in act two when measured against Watson, and even Donna Elvira's Mi tradi quell'alma ingrata, where Lisa Milne uncharacteristically failed to make me swoon.

Further performances tonight, Tuesday, Thursday and Saturday, then touring to Aberdeen, Inverness and Edinburgh.