‘You gotta get a gimmick’, Louise is advised in Gypsy. In opera-directing circles, it’s sometimes disparagingly called a Konzept. The Konzept for Martin Fröst’s double album of Mozart, titled ‘Ecstasy and Abyss’, is a flimsy one. The idea is that two cities – Leipzig and Prague – feature at key moments in Mozart’s life: Leipzig in May 1789, when the impecunious composer gave a concert there, well received by the critics but still making a financial loss; Prague in 1791, where his opera La clemenza di Tito premiered to great acclaim and where he conceived his miraculous Clarinet Concerto for his friend Anton Stadler. From ‘abyss’ to ‘ecstasy’. At least Sony didn’t call it a ‘project’ (DG’s new buzzword).

Gimmick aside, this is an enjoyable double album of Mozart. It’s also a significant release in two respects. It marks Fröst’s recorded debut as a conductor (rather than as soloist-director), with the Swedish Chamber Orchestra. And it also marks his third recording of Mozart’s Clarinet Concerto, performed on a basset clarinet, as indeed were his two previous recordings, with the Amsterdam Sinfonietta (2002) and The Deutsche Kammerphilharmonie Bremen (2010). Why a third? As Fröst notes in the booklet, there are different versions of Edvard Munch’s The Scream, existing ‘in plural, across time and physical forms, as an idea, an ever-changing idea’. He adds: ‘And there is no single, definitive Mozart Clarinet Concerto.’ The cynic may add that his two previous recordings were for BIS and Fröst has since jumped labels to Sony.

Fröst certainly exercises the freedom that having two recordings of the concerto safely ‘in the can’ permits him. He’s always been willing to ornament Mozart’s phrases and does so with abandon here, notably in the third-movement Rondo, which chortles along merrily. There are no real cadenzas in the concerto, just a couple of moments where Mozart writes a fermata that invites a decorative phrase or two. There are two such in the first movement, the second of which Fröst greets in slightly hyperactive fashion (10'45"). The cadenza opportunity in the Adagio (3'33") is given an extended fantasy-like treatment lasting around 40 seconds.

Fröst’s tone is as ripe and gorgeous as ever. His tempos are largely the same as before and he draws responsive playing from his orchestra. Do you need this Fröst recording? Mega-fans will lap it up. Others may want to consider the couplings – his Amsterdam recording pairs it with Mozart’s exquisite Clarinet Quintet, whereas the Bremen disc has the Kegelstatt Trio.

Under Fröst, the Swedish Chamber Orchestra’s style in Mozart echoes another SCO – the Scottish Chamber Orchestra under Charles Mackerras; namely, modern instruments playing in a historically informed manner (antiphonal violins) with the addition of incisive period brass and timpani. There is pleasing aggression to the two symphonies – the Jupiter and the Prague – and some lively tempos, recorded in an acoustic that allows for plenty of instrumental detail to shine through.

The two discs are uneven. The ‘Leipzig’ one opens with an account of the Jupiter Symphony where the inner movements are problematic. In the Andante cantabile, the first violins’ opening phrase is met with an ugly, accented jab in the string and woodwind response, startling on first hearing and not in a good way. One is on edge every time the chord returns. The Menuetto is nice and swift but the Trio section has odd phrasing and emphases, with held notes and awkward pauses. The outer movements are strong and the finale bustles along in high spirits, although Fröst does not observe the second repeat.

Elin Rombo is mellifluous in the concert aria Ch’io mi scordi di te, with neat piano contributions from Lucas Debargue, who is the slightly prissy soloist in the C major Piano Concerto, K503. It would be good to hear more fun in his playing.

The ‘Prague’ disc, which closes with the Clarinet Concerto, also contains Sesto’s aria ‘Parto, ma tu, ben mio’ from Clemenza, ravishingly sung by classy Swedish mezzo Ann Hallenberg, with Fröst providing the obbligato basset clarinet support, and – naturally enough – the Prague Symphony. This fares much better than the Jupiter, with lively, assertive playing, the Allegro of the first movement fizzing along (no second-half repeat). The middle movement feels swifter than the Andante tempo marking but maintains a cantabile singing line, while the finale races at an even faster lick than Mackerras in Scotland.

I’ll not relinquish that Linn set of the last four symphonies, but the playing on the ‘Prague’ disc here is pretty fine. We all know and love Fröst the clarinettist, but Fröst the conductor is clearly someone with interesting ideas.