Notker the Stammerer (Latin: Notker Balbulus) (c. 840 – 6 April 912), also called Notker the Poet or Notker of Saint Gall, was a musician, author, poet, and Benedictine monk at the Abbey of Saint Gall in modern Switzerland. He is commonly accepted to be the Monk of Saint Gall (Monachus Sangallensis), the author of De Carolo Magno, a book of anecdotes about the Emperor Charlemagne.
Notker was born circa 840, to a distinguished family. He would seem to have been born at Jonschwyl on the River Thur, south of Wil, in the modern canton of Saint Gall in Switzerland; some sources claim Elgg to be his place of birth. He studied with Tuotilo at Saint Gall's monastic school, taught by Iso, and Moengall. He became a monk there and is mentioned as librarian in 890 and as master of guests in 892–4. He was chiefly active as a teacher, and displayed refinement of taste as poet and author. Ekkehard IV, the biographer of the monks of Saint Gall, lauds him as "delicate of body but not of mind, stuttering of tongue but not of intellect, pushing boldly forward in things Divine, a vessel of the Holy Spirit without equal in his time". He died in 912. He was beatified in 1512.
He completed Erchanbert's chronicle, arranged a martyrology, composed a metrical biography of Saint Gall, and authored other works. The number of works ascribed to him is constantly increasing.
His Liber hymnorum, created between 881 and 887, is an early collection of Sequences, which he called "hymns", mnemonic poems for remembering the series of pitches sung during a melisma in plainchant, especially in the Alleluia. It is unknown how many or which of the works contained in the collection are his. The hymn Media Vita, was erroneously attributed to him late in the Middle Ages.
Ekkehard IV wrote of fifty sequences composed by Notker. He was formerly considered to have been the inventor of the sequence, a new species of religious lyric, but this is now considered doubtful, though he did introduce the genre into Germany. It had been the custom to prolong the Alleluia in the Mass before the Gospel, modulating through a skillfully harmonized series of tones. Notker learned how to fit the separate syllables of a Latin text to the tones of this jubilation; this poem was called the sequence (q.v.), formerly called the "jubilation". (The reason for this name is uncertain.) From 881–7 Notker dedicated a collection of such verses to Bishop Liutward of Vercelli, but it is not known which or how many are his.