The title of the Keller Quartet's latest album of recordings made between 1995 and 2012 comes from Beethoven's directive for the Lento Cantante e tranquillo of his final string quartet.
This movement, played twice, with a vibrant intimacy that will have you hovering over the sound, opens and closes the CD, providing emotional pillars for the deeply contemplative music laid out between them.
Such a collection might seem a perilous undertaking to those underwhelmed in the mid 1990s by Deutsche Grammophon's Karajan Adagio album.
However, Cantante e tranquillo is made of sterner stuff. There's no Massenet tear-jerkers; instead, we have the soul-cleansing astringencies of Ligeti and Schnittke.
Two extracts from Bach's The Art of Fugue evoke the sweet sadness of a viol consort and the brutal mid-phrase silence in the composer's final, unfinished fugue is as chilling as any winter blast. Bach is followed by a short Homage to J.S.B. by Gyorgy Kurtag. This fragile, fanciful piece, running at just over a minute, may well entice your finger on to the replay button.