There is a change to our coverage of classical CD releases. Since theartsdesk began in September 2009, we have been reviewing on a monthly basis. As of today we're switching to weekly and our round-up of the new classical albums will now appear every Saturday. To mark the change, we have a bumper helping, with Tansy Davies's new release taking a bow as our Disc of the Day. As for the rest, there's a Russian flavour – historic, idiomatic performances of Tchaikovsky symphonies, and exciting readings of Shostakovich piano concertos. Enjoy French sisters playing piano duets and a glorious Handel oratorio, and be soothed by the most alluring of sackbut recitals.