The Aldeburgh festival's new director Pierre-Laurent Aimard quietly stamped his authority on the festival's final weekend, appearing as both pianist and conductor. Even if slightly forbidding in his intensity, the commitment and the clarity of his musical vision was disarming.

Collaborating with the Mahler Chamber Orchestra over two concerts, Aimard drew parallels between the methods of Haydn and Ligeti, Birtwistle and Stockhausen respectively. In Birtwistle's Slow Frieze, under the incisive direction of conductor Susanna Mälkki, Aimard coolly delivered the piano's part in the virtuosic engagement with mechanisms of time and tempi. He conducted Stockhausen's Kontra-Punkte with an equal dispassion and, even if one questioned the wisdom of directing Beethoven's Emperor concerto from the keyboard, the performance was still stirring.

What composer Helmut Lachenmann calls "musique concrète instrumentale" was apt for the new Britten studio, a space where concrete has breathed new life into another part of Snape. And, while most would regard Lachenmann's 2008 piece Got Lost – punning on the German gottlos (having no god) – as a godforsaken kind of music, this UK premiere had a peculiar fascination.

Simultaneously setting poems by Nietzsche and Fernando Pessoa, together with a notice about a lost laundry basket, while focusing on disembodied syllables and the different ways in which sounds are produced, there was something distinctly primal about the exercise, not least when soprano Sarah Leonard faced towards the raised piano lid to create eerie echoes. But it was Lachenmann's piano-writing that communicated most vibrantly, with Rolf Hind realising a strangely human-sounding expressivity.