A single 128th note is always stemmed with flags, while two or more are usually beamed in groups.
[4] Notes this short are very rare in printed music, but not unknown.
For example, they occur in the first movement of Beethoven's Pathétique Piano Sonata (Op.
[5][6] Likewise, 128th notes are used in the explicitly notated ornamental runs in the opening Adagio of Bach's g minor Sonata for Unaccompanied Violin (BWV 1001).
13 "Quasi una fantasia" (bar 24 in the adagio movement) where it is followed by an ascending run of 128th notes,[8] as well as in the finale of Charles-Valentin Alkan's Grande sonate 'Les quatre âges'.