When seemingly unusual details emerge from an interpretation of a thrice-familiar work, it’s often because the performer is taking certain of the composer’s markings on faith. The way Janne Mertanen begins Chopin’s Fourth Ballade is a case in point. He maintains a feeling of Andante con moto by not overdoing the ritenuto measures. Nor does he brood over the main theme, but keeps it moving in flexible arcs. At 4'41" in the section following the chorale-like interlude, Mertanen brings out the right-hand crescendo and sudden semiquaver rest to uncommon dramatic effect, in contrast to the tender simplicity in the imitative writing starting around 6'24". While Mertanen takes the coda at a near breakneck clip, his discreet pedalling and clear part-writing prevent the music from sounding rushed; a most gratifying rendition by any standard.

The F sharp Impromptu stands out for Mertanen’s eloquent transparency in the outer sections and his canny dynamic build-up in the Trio. He brings a relaxed and gently rhetorical aura to the G flat Impromptu that differs from the lightness and simplicity one hears from Arthur Rubinstein or Janina Fialkowska. Pretty though Mertanen’s well-modulated fingerwork in the Barcarolle is on the surface, the music loses shape and momentum due to the pianist’s rhythmic fidgeting. On the other hand, the B minor Sonata’s Allegro maestoso can absorb Mertanen’s headlong sweep and agitato sensibility to the point where his observation of the exposition repeat doesn’t sound redundant. His fleet and offhand dispatch of the Scherzo’s outer sections almost throws the music away, in contrast to Stephen Hough’s buoyant articulation (Hyperion, 5/10). Mertanen’s artistry comes into total focus throughout the Largo, which abounds in the long-lined fluency and proportioned phrasing that I miss in the Barcarolle. Despite occasional rushing, Mertanen’s forward thrust and hurtling dynamism in the finale impart a nervous energy and angular edge that bring up memories of Bruce Hungerford’s recording for the American Vanguard label, or existing live performances with the young Martha Argerich. The recorded sound conveys palpable concert-hall realism, all to the pianist’s benefit.