mid-18th c. keyboard articulation
Harrison (97), 33-49. Keyboard touch was divided into four types: staccato (the notes held for half or less than half the note value); legato, always appearing under slur (the notes held for their full value); ordinary touch, which is unmarked (the notes played somewhat detached); and portato, with \"staccato\" dots under a slur (the notes played without any interruption of sound and with slight emphasis).
\"Ordinary keyboard touch [unmarked in the score] was realized by holding the notes half their value unless marked Ten.\" Bach, C.P.E. (1753, 1762), trans. 157. According to Marpurg (1755), 29, however, \"the finger is [to be] lifted from a key just before the following note is played.\" .