Low - Classic Grand, Glasgow, Tue 17 May

Half-way through this suitably intense and reverential set by Low, Alan Sparhawk responded to a loved-up heckler with a telling remark. ‘After 18 years we add a fourth person and he’s the first to get a compliment?’ he deadpanned.

His comment served as a timely reminder that the Minnesotan alt-rock icons have been doing their unhurried, unflashy and exquisite thing for nigh-on two decades, with no sign of dwindling. Indeed, a number of the evening’s highlights derived from their current (ninth) long-player C’Mon, not least ‘Especially Me’ – a dizzying, harmonic psalm that swirled round the venue like a kaleidoscope.

While their newest keyboard-playing recruit (Retribution Gospel Choir’s Eric Pollard) provoked come-hither audience entreaties, the band’s (slow) core matrimonial duo of Sparhawk and Mimi Parker rendered us silent and made sparks fly.

Parker cut a striking figure – beating a drum, voice like an angel – and the stars aligned when she harmonised with Sparkhawk on ‘When I Go Deaf’. Sparhawk was equally fascinating, as was his parting shot after an encore that featured celestial aria ‘Sunflower’. ‘Deep down, I want to shove a knife down every one of your throats,’ he smiled fondly. Tenderness and latent menace: that’s Low all over.