LONDON—A long-lost manuscript of works by German 17th-century keyboard maestro Johann Jacob Froberger, also believed to have been a part-time spy, goes on sale later this month with a price tag of $953,500.
Froberger, who eventually rivaled the stature of his former teacher the Italian composer Girolamo Frescobaldi, was hailed in his lifetime and beyond as one of the greatest masters of 17th century keyboard music.
The previously unrecorded book, bearing the arms of Leopold I on both covers, contains 35 pieces of keyboard music of which 18 are completely unknown.
"The 18 new pieces, which amount to over 180 pages of new music and increase the composer's canon of known works by about a fifth, are examples of his hitherto unknown 'final period'," said manuscript expert Simon Maguire of auction house Sotheby's.
"Its discovery will change the history of 17th century music," he added.
Froberger, who is credited with inventing the Baroque suite for keyboard, was born in Stuttgart in 1616. At the age of 18 he moved to Vienna where he became court organist in 1637—the same year he went to Rome to study under Frescobaldi.
He returned to Vienna in 1641 to make it his base for the next 16 years, often traveling on what are assumed to have been secret diplomatic missions in that they took him to countries in strife and with no apparent musical purpose to be served.
Among places he is known to have visited are Brussels, Dresden, Antwerp, London and Paris. Little is known about his travels after 1658, although Froberger is known to have spent his final years teaching and in virtual seclusion in the eastern French town of Hericourt.
His music is known to have influenced master composers like Pachebel and Bach and possibly even Mozart. The manuscript is being put up for sale by its unnamed European owner at Sotheby's in London on Nov. 30.