As Anton Stadler was to Mozart and Richard Mühlfeld was to Brahms, Heinrich Baermann was Carl Maria von Weber’s clarinet muse. Weber met Baermann in 1811 in Darmstadt, where the clarinettist performed the obbligato clarinet part in his duet Se il mio ben. He was evidently smitten because that same year, Weber composed his two clarinet concertos and the E flat Concertino for Baermann, touring them together in early 1812. Weber was attracted to the clarinet’s vocal qualities and it’s no surprise that the slow movements of his concertos have the feel and temperament of operatic arias.

Weber began composing his Clarinet Quintet on his Swiss summer holiday in 1811 but it wasn’t completed until 1815. It is a truly wonderful work featuring, yes, an operatic slow movement, a cheeky Minuetto and a scampering finale. It appears as the centrepiece on two new discs which could not be more different if they tried. For Glossa, the American-born Dutch clarinettist Eric Hoeprich plays on a period instrument, a copy of a 10-key B flat clarinet in Baermann’s collection by Griessling & Schlott of Berlin. Jörg Widmann, on the other hand, plays a modern clarinet and performs the quintet on his all-Weber Alpha disc in an arrangement for string orchestra.

Widmann is not the first star clarinettist to opt for the bulkier string ensemble – Sabine Meyer (twice) and Martin Fröst have also recorded it – but I cannot help but lament the decision. Essentially, it turns the quintet into another concertante work, and what is the point of that when we already have Weber’s concertos and the concertino? The intimate byplay of clarinet and solo strings is lost, especially when Alpha spotlights the clarinet. What makes the decision even more frustrating is that Widmann’s playing is often spectacularly good.

For a German clarinettist, his tone is quite narrow, but he draws very sweet pianissimos and his fortissimos never shout. Unlike Fröst and Meyer (in her first recording), he includes the first-movement exposition repeat (as does Hoeprich). Widmann ornaments on repeats and adds effective rubatos. The Fantasia (Adagio) is drawn out to an incredible 6'22", which is possibly too much of a good thing, but the Minuetto and the Rondo finale are full of humour – unlike the rather po-faced Meyer – and exhilaratingly fast. It’s to the credit of the Irish Chamber Orchestra that, despite their numbers, they manage to keep pace with Widmann, who also directs.

Hoeprich and the London Haydn Quartet take a much more relaxed approach. His tone is soft and buttery, the close recording revealing the gentle clatter of pads and keys, while the string tone is lovely, never rough hewn. The Adagio flows swiftly (4'42"), perhaps lacking an element of fantasy, but there’s a general feeling of amiable ease about the rest of their performance, without any sense of danger or risk. Turn to Charles Neidich and L’Archibudelli on Sony Vivarte for added sparkle; Neidich’s tone, playing on a reproduction of an 1810 Grenser, is occasionally a little tart and the strings are sinewy but the performance is a zinger, the clarinet often chuckling in glee.

Hoeprich and the LHQ also play the Clarinet Quintet in B flat by Franz Krommer (František Vincenc Kramář), an amiable work and notable for employing two violas rather than two violins, Michael Gurevich making the switch from violin to viola here. Krommer doesn’t have Weber’s degree of invention, but the elegant Minuetto glows while the Allegro finale raises a smile, especially in such an affectionate performance as this. In between comes the Adagio from Baermann’s own Clarinet Quintet No 3 in E flat, a work long misattributed to Richard Wagner. It’s a gorgeous movement, so lovingly performed that I wished they had recorded the entire quintet (there was space).

For the rest of his programme, Widmann maintains his focus on Weber, a composer he admires greatly. The brief Concertino gets a thoroughly persuasive performance, while Widmann is joined by the pianist Denis Kozhukhin for the Grand duo concertant, a work possibly written for Baermann’s rival, Johann Simon Hermstedt. Widmann and Kozhukhin give a highly polished account, fully embracing the work’s bravura. They are quite measured in the Rondo finale, even in the coda, which is sometimes rattled off ridiculously fast. In between, Widmann assumes the role of conductor for the bracing overture to Der Freischütz, in which he particularly enjoys teasing out Weber’s daring harmonies in the ghostly opening.