Thomas Ades and Gerald Barry, Sgt Pepper at 50, Guto Puw and Welsh-language music

Tom Service talks to the composer and conductor Thomas Adès and composer Gerald Barry about the 'explosive' music of Beethoven. Adès is embarking on a three-year concert project combining Gerald Barry's music with Beethoven's great works - and the two musicians chat with Tom about how the two composer's 'volcanic' music can shed light on each other.Tom celebrates the Beatles' seminal album Sgt Pepper's Lonely Hearts Club Band 50 years after its release. He looks at classical music's influence on the Beatles, and how, in turn, other music has been inspired. He talks to composer Nigel Osborne, who has orchestrated the album for a performance in Liverpool, and composer Kerry Andrew on its inspiration. Plus he hears from Erich Gruenberg - one of the original musicians on the album, and archive from Paul McCartney himself.A new opera by composer Guto Puw - Y Twr (The Tower) - is a rare occurence, an opera sung solely in the Welsh language. Tom talks to Guto about writing the piece and discusses the wider use of Welsh in music with Deborah Keyser director of Tŷ Cerdd - Music Centre Wales.And Tom talks to musician and writer Damon Krukowski and composer Sarah Angliss about Damon's new book, The New Analog, and how digital technology has affected what we hear.