Songstress A.A. Williams was last in Glasgow supporting Chicago post-metal trio Russian Circles, and the overlap of that band’s fans with tonight’s headliners means a good few in attendance might already be familiar with William’s slow, ethereal balladry. She is the latest in a line of forward-thinking solo artists who have lit up the metal underground, following in the footsteps of Chelsea Wolfe and Emma Ruth Rundle, who have taken the funereal pace and oppressive atmospherics of doom and drone into quieter, more meditative territory, albeit one still conveying a suitably grim outlook typical of the genre. The big difference tonight is that rather than full band, Williams is playing a stripped-back piano and guitar set with just a bassist for accompaniment. This is initially very arresting, her voice and weighty piano chords filling out the cavernous hall and instilling a pin-drop silence amongst the early arrivals, the music bringing to mind Cat Power at her most austere and desolate. As the performance continues, however, it really begins to miss the shifting dynamics and colour that a full band set allows, each solemn dirge now blurring indistinguishably into the next and attention starting to drift during the last few numbers.

Such is their music’s ubiquity on everything from feature films to nature documentaries, it’s easy to take a band like Explosions In The Sky for granted. Even more so when for a lot of people they are a byword of a particular brand of instrumental post-rock, bringing in plenty of crossover listeners to the scene who might not know their Mogwai from their Mono. This taking stock of the band’s status leads to their 20th anniversary tour and the playing of some grand, seated venues to mark the sense of occasion. It’s a real pleasure to hear this kind of overwhelming, guitar-focused music in such an acoustically sound venue, with every nuance crystal clear from the quietest solitary bass line to the distortion-heavy crescendos that elevate the listener to a heightened state of white noise transcendence.

The set-list is a good overview of the band’s catalogue, although it does certainly lean towards their earlier material, perhaps a concession to the band’s more loyal listeners, or maybe the band are just feeling nostalgic as they end their second decade. Drummer Chris Hrasky is a mesmerising focal point throughout, his taut military-style snare work and cymbal swells as much of a trademark of the band’s sound as the delay and reverb saturated melodies. Hrasky’s playing really drives the momentum of classics like Your Hand In Mine and The Only Moment We Were Alone, both sounding evergreen. The set highlight comes surprisingly early, with the momentous Birth and Death of the Day arriving just three songs in, its opening wave of searing guitars crashing down to take the breath away, the band then regrouping to build once more to a triumphant climax that would make ideal set-closing fodder. This is a minor nit-pick though for an otherwise authoritative performance that reminds you why this band became such an adored institution in the first place.