Director general Tony Hall is expected to say the move will mean historic and recent performances are “returned to the public”.
They will be available on services such as BBC iPlayer and the BBC Sounds app.
Lord Hall is expected to reveal the plans at the launch of the BBC’s year-long classical music project, Our Classical Century on Thursday evening.
The project will look back at 100 years of classical music in the UK and will be covered online and on BBC Four, BBC Two and Radio 3.
The corporation has one of the biggest classical music archives in the world, with recordings from the BBC Proms, BBC orchestras and choirs along with BBC Young Musician and BBC Introducing.
Lord Hall is expected to say: “In time, you will also be able to find them by using voice activation technology to make your own journey through classical music.
“Whilst the way we consume and share content is changing rapidly, music’s ability to bring us together has stayed the same, and classical music’s role in that should not be underestimated.”