The silent auction allows bidders to view and read about auction items — Sondheim penned the opening notes for "Send in the Clowns" and signed the paper, for example — and bid online throughout the duration of the auction.

The online auction ends May 12 at midnight. A digital image of each composer's autograph appears at llfauction.org.

According to organizers, each "musical autograph" consists of three musical staves pre-printed on a sheet of 8.5-by-11-inch archival grade Acid-free paper with a neutral or basic pH (seven or slightly greater). It addresses the problem of preserving documents for long periods. Each composer was asked to provide a few measures in their own handwriting of one of their compositions. A letter of authenticity accompanies each autograph.

Once online bidding has closed, those who attend in person at the silent auction cocktail party in New York on May 13 will have a final opportunity to outbid online bidders.

All proceeds go to Lotte Lehmann Foundation. The entirety of the bid is tax-deductible. For more information about the Lotte Lehmann Foundation, visit http://lottelehmann.org.