I’ve never before dreamt of being a fly on the wall during early discussions of festival programming, but this concert really set me thinking. Two minor-key works? One instrument? Ten o’clock on a Saturday night? The element which reframes everything is the Lammermuir Festival’s binary belief in beauty of music and place. The magical acoustic and atmosphere of a candlelit St Mary’s Church, Haddington and the sound of unaccompanied Bach on the violin of Dutch virtuoso Cecilia Bernardini proved crowd-pulling.

Bernardini’s take on music and setting felt clear from the opening “Grave” of Bach’s 1720 Violin Sonata no. 2 in A minor. The Paganini-like stridency common to many renditions was entirely absent, leaving room for the music to sing on its own terms and the wonderful building to play its part. The chords, nurtured rather than attacked, rang out hauntingly.

I really enjoyed the tempo of the following “Fuga”. While I’ve heard it played more briskly, such headlong interpretations often preclude defining breaths between successive entries of the main theme and between sections of this substantial fugue. They also preclude the appealing dance-like feel of this performance. Anyone present sensing that choice of tempo was informed by technical caution would have had this idea blown apart in the closing bars.

The two-part writing in the “Andante” was not only clear, but the separation and hierarchy of melody and pedal-note accompaniment was so well articulated that one could have sworn two players were involved. The closing “Allegro” features many echo phrases highlighted by dynamic contrast. The subtle way in which this was done – again allowing the acoustic its say in proceedings – suggested a performer addressing a discerning audience.

The Partita no. 2 in D minor, from the same 1720 collection, is more obviously concerned with dance, boasting an “Allemanda”, “Corrente”, “Sarabanda” and “Giga”. The closing “Ciaccona” (“Chaconne”) is effectively, and unusually, a second sarabande.

The “Corrente” certainly adhered to the titular running alongside skipping and, at the peak of some phrases, soaring. Being the slowest, the “Sarabande” features more protracted ornamentation. In one lovely phrase I noticed a florid ornament spin delicately under a held melody note. Even more winningly, the dance was kept alive as this moment eased into the following phrase. Contrastingly, in moments where the melody goes it alone without its harmonic friends, Bernardini enjoyed the freedom to lean outside the dance for just an instant. This flexibility cast her in the role of happy participant in the dance, rather than its prisoner.

Despite its minor tonality the “Giga” contains, and certainly radiated here, great joy. Even at this necessarily breezy tempo the needs of implied counterpoint were nicely handled and emergent melodies rang out. Here, too, dynamics were tastefully employed to highlight call and response phrases.

The closing bars of the “Giga” are so heroic that one could hardly be surprised at spontaneous applause. In any case, I’d imagine that Bernardini would be glad of a few seconds’ respite in this Herculean musical and intellectual undertaking, before unfolding the epic “Ciaccona”. This theme and 60 variations felt, in some ways, like an intensified summary of all that had gone before: soaring melody; achingly beautiful harmony; dance-like vigour; gripping counterpoint. Entirely new are extended passages of dramatically slow-moving chords, rapidly arpeggiated by deft bow work. This often overwrought passage, while not lacking drama in any sense, was wonderfully free of brash and hollow showiness. At the movement’s centre, the music embraces D major – the equivalent of a surprise glass of Prosecco midway through Lent. The sense of pace was delicately altered as this corner was rounded. Then, the original tonality gradually restored, the work concludes with the theme's restatement.

Despite sustained applause I somehow felt that an encore might not follow; what could thrive in the shadow of the “Ciaccona”? When it seemed clear that Bernardini wanted to reward the attentive and appreciative audience, I wondered if the cheery “Prelude” from the E major Partita might follow, or perhaps the triumphant “Allegro assai” from the C major Sonata. I was delighted when she announced the reflective “Adagio” from the Sonata no. 1 in G minor. This tenderly played, searching movement, which seems to ask more questions than it answers, was the antithesis of the easy victory of major over minor which I’d unnecessarily feared. Exiting by St Mary’s graveyard in the autumnal night air, I was reminded of Keats’ ode to that season – specifically the phrase “thou hast thy music too” and heartened to think that, late on a Saturday night, an audience of more than two hundred had been happy to reside in music’s dark side.