When it comes to descriptively titling a concert, the BBC National Orchestra of Wales could hardly have done better than the solitary word used on this occasion: “Impressions”. Clear yet at the same time vague, rich with connotation, that word made its presence felt through each of the five works comprising last night’s celebration of French composer Henri Dutilleux, the centenary of whose birth was last week. An evening of music paying homage to Dutilleux is inevitably going to be more than usually steeped in lavish orchestral colour, with particular interest in line, and in some respects this was not merely a characteristic than a highlight in and of itself.

Not, however, one wielded with universal aplomb. In Eric Tanguy’s memorial work Affetuoso a robust melodic presence formed the core of a full-blooded, muscular workout, not unlike Vltava on steroids. But even before half of its 11-minute span had elapsed, the arc and gait of the melody had become entrenched, even rather dogged despite its continual flexing. Everything else around it was similarly limited, with little timbral differentiation – considering the size of his palette, Tanguy’s use of it was surprisingly humdrum – and minimal mixing of colours, giving the materials an overemphatic outline. The BBC NOW’s sense of orchestral unity here was undeniably outstanding, each player an integrated component within a single, vast, multifaceted organism, yet while Affetuoso certainly made an impression, it didn’t amount to much and the dust it kicked up settled very quickly.

Soprano Elizabeth Atherton joined the proceedings on two occasions, beginning with Julian Anderson’s setting of words from the Biblical Song of Songs, Shir Hashirim. The work was striking in the way it differs from much of Anderson’s output, eschewing hackneyed textural activity in favour of expansive opulence. The opening was particularly sumptuous: dreamy, heady, ecstatic, an intoxicating atmosphere that persisted even when things dissolved into a more gestural melée. Atherton’s fittingly sweet voice only occasionally struggled to be heard, her melismas floating high above the orchestra, Anderson coating them in shifting shades of colour.

With Thierry Pécou the concert ramped up a few notches, entering more daring territory. Les liaisons magnétiques reduced the BBC NOW to just 15 players for a two-part work that, in action perhaps more than design, resembled a 21st-century re-appraisal of the possibilities of Impressionism. Initially slow – featuring delicious, deep gruffness from Jennie Joy Porton and Steve Morris on baritone sax and contrabass clarinet respectively – Pécou escorted us through a sequence of micro-narratives coalescing in a long bassoon line, surrounded by an accompaniment that was surprisingly gossamer-like considering most of the ensemble was playing. Its vivid second half was all regularity and marshalled momentum, building into a kind of diabolical procession, like a collection of staggering zombies at a New Orleans funeral. Moving from transparency to complex counterpoint to cross rhythms – becoming climactic without being archetypally so – the orchestra, their pitches now in the stratosphere, were cut dead by the bass drum, a wicked compositional flick of the wrist crowning a superbly allusive piece of contemporary chamber music.

Kenneth Hesketh’s Graven Image, didn’t just restore the orchestra to full size but bolstered it with additional instruments. To excellent effect: another work with line at its epicentre, Hesketh festooned it with extravagant decoration and embellishment, tapping into a positively cinematic lushness. It would be easy to become caught up in such exotic loveliness, but bass surges and a majestic climax kept one grounded. This was deeply complicated music, delightfully so, one’s focus flying around the orchestra as ideas constantly surfaced in all directions, many lost moments later. In the wake of such an overwhelming tumult, Graven Image finds itself at the last a little lost, ending in a white, dazed haze.

Appropriately, Dutilleux himself brought the concert to its conclusion with his short song cycle Le temps l’horloge (‘Time and the Clock’). Now the four homages found context: here, once again, was music where line (pre)dominated, constantly fleeting, effervescent, rapturously radiant. Articulating lines of Tardieu, Desnos and Baudelaire, Elizabeth Atherton’s voice was the constant in material that struck an impressive balance between clarity and obfuscation, mischievously slipping just out of reach. Following a high point in the brief third movement – dark and unsettlingly complex, yet utterly gorgeous – Dutilleux introduced a new assertiveness into the soprano writing, Atherton signing off both the cycle and the evening with an amusing brusque outburst, melody finally breaking down entirely at Baudelaire’s adjuration to the world: “Get drunk!”

Conductor Pascal Rophé expertly negotiated the discrete takes on line and colour that permeated these five, very different works. The Hoddinott Hall didn’t always prove a sympathetic space for such dazzling orchestral paint-splattering, but the BBC NOW’s articulation of the music’s wealth of inner details was never less than crystal clear.