Reviewing is a remarkable pastime. Last week I reviewed a new jazz opera about baseball for kids from Hackney, something I never thought I’d do. Now I’m reviewing a concert about as far removed from Shadowball as could be possible: not physically, but musically, philosophically and emotionally. For there can be few more ‘establishment’ concerts than this Sunday Morning Coffee Concert at Wigmore Hall, the programme of which featured two of the most popular pieces ever written: Mozart and Brahms’ Clarinet Quintets. This is by no means a derogatory description, for if the series and venue are established, and the music popular, it is because they have withstood the test of time, and passed with the highest marks in civility, acoustic quality, and sheer beauty.

The Belcea Quartet was joined by exceptional clarinettist Michael Collins for these two behemoths of the quintet repertoire. As they took their seats in front of a packed Wigmore Hall audience, and the first notes of the Mozart rang out with vibrant serenity, it struck me that this really was the perfect sunny Sunday morning experience. Mozart’s quintet is best known for its melting second movement, but its first is equally sublime. Two simple and perfectly balanced subjects, in which the clarinet and first violin switch between lyrical melodies and ornamental flourishes, lead into trio sections: the first featuring a clarinet melody with a suspension-filled accompaniment in both violins; the second featuring the same accompaniment in violin II and viola, the cello taking the lead role. The tiny development section, made up of an imitative canon in the strings and a flitting staccato clarinet, made me think that Mozart was either very lazy, or just that he knew when he had such a good thing going that he needn’t bother developing it. Call it arrogance, self-awareness or what you will: it works perfectly. The poise with which the ensemble performed this opening movement was exactly what was required to bring out the subtle proportions that make it such an exemplary Classical beauty.

There’s really not much I can say about the second movement, nor that I need to say. It was as wonderful to witness as you might expect with this fantastic group in this exceptional acoustic. Only the slightest of criticisms can be made: I felt that first violinist Corina Belcea couldn’t quite match Collins’ extraordinary warmness of tone – an incredibly difficult challenge for a muted vioin, but one which could be possible all the same. Once again, the ensemble achieved a perfect position of engaged decorum, never revelling indulgently in the music’s sublimity. The Minuet and Trio which followed brought new levels of stateliness to proceedings: I could practically see the ballgowns and waistcoats of the dancing 18th-century elite. The elegance became more playful in the Trio, though, and the joviality continued into the Finale, a Theme and Variations that the players really got their teeth into. The emotional viola variation was particularly movingly played by Krzysztof Chorlzelski, and Belcea equalized with Collins after outsparkling him on some dazzling arpeggios.

If the quintet portrayed the poise and playfulness of the Mozart excellently, they truly shone in the dark hues, intense richness and tempestuous emotion of Brahms’ quintet. The string players really turned on the vibrato for this romantic music, and it felt a little naughty to be indulging in such passion before lunch on a Sunday. As well as some gorgeous melodies, Collins here as elsewhere excelled in an accompanying role, in passages that exemplified the remarkable sound of the clarinet quintet by their mellow mix of timbres. The lullaby-esque second movement – which in my opinion rivals the Mozart for the most perfect second movement prize – turns schizophrenic, with tremolando strings rocking the cradle with tumult. Brahms’ drama makes this work a wonderful one to witness in concert, and the quintet’s playing was truly engaged in the movement’s intense seriousness. The perfect antidote was administered in the consoling warmth of the short and sweet third movement, with its soaring clarinet melody over pizzicato strings contrasting with its scurrying passages with clarinet flourishes.

Passionate minor strains were reasserted for the final movement, another theme and variations, which seemed at moments to parody Mozart’s Finale: the staccato clarinet arpeggios and viola variation seem strangely incongruous unless they are a sly reference to the Little Master’s work. If Brahms was acknowledging Mozart’s quintet, he certainly didn’t mimic its cheeky ending; Brahms’ work finishes on a rather sudden, even desolate note. Though this takes the listener by surprise because of its brusqueness, it is an ending perfectly in keeping with the rest of the work, which, as exemplified by this truly excellent performance, is one of dark, brooding beauty, shot through with beams of glorious, peaceful light.