In 1967, in one of his most famous essays, Alan Tyson described looking closely at the autograph score of the Concerto for Violin and Orchestra, op. 61, today housed in Vienna, and noticing a few peculiar annotations written in the lower staves of the document. Among these annotations, Tyson observed, it was possible to recognize not only a few memoranda regarding the future arrangement of the concerto for piano (specifically, for the left-hand part), but also a series of notes of a different kind, whose function seemed connected to the orchestral arrangement, almost a “rough aide-mémoire for writing out the work in score.” Three years after the publication of Tyson's essay, Lewis Lockwood refocused the scholarly community's attention on that specific type of annotation, which was later recognized as characteristic of Beethovenian manuscripts. His observations on the subject were developed in two different publications from 1970 and concentrated on the example of the Concerto for Piano and Orchestra in D Major (the unfinished “Sixth Concerto”—Unv 6, formerly known as Hess 15), but he pointed out at the same time that analogous examples were clearly traceable in other documents. Lockwood described such annotations as:
A small but legible “cue-staff” (as I am provisionally calling it) that runs through almost the entire manuscript at the bottom of each page, below the full orchestral score… . In its format, content, and certain details of notations, the “cuestaff” in this score is identical to the linear sketches with which we are familiar from many sketchbooks. In effect, the “cue-staff” is a sketch-line that has been transferred from sketchbook to rudimentary score. It looks like a kind of “missing link” between the two types of sources and, consequently, between the two types of work areas.
Lockwood's suggestion did not remain isolated: also in 1970 Joel Lester published an important article on the autograph of the Kyrie of the Missa solemnis, op. 123, noting the presence of a particular annotation at the bottom of the score, most likely set down in an initial phase of the work on that manuscript. In 1971 Tyson touched once again on the subject, essentially accepting in full the observations developed by Lockwood.