As with sul ponticello, Ganassi discusses what may be understood as sul tasto or sulla tastiera, although it is not clear if he was using the term with the same meaning that sul tasto has today (Boyden, 1965, p. 77).
There are many examples of sul tasto in post–Second World War repertoire for the modern violin, with some examples going so far as to instruct playing with the bow at such a great distance from the bridge that it is in contact with, or directly beside, the left-hand fingers.
Sul tasto on the baroque violin:
Finding the ideal bow position on the string with which to create a pure tone is more important with gut strings than with steel strings. As such, variations in bow position on gut strings can create a greater variation of timbre than is possible to achieve with the steel-strung modern violin.
Depending on the string and exact left hand position, it can be impossible to achieve extreme molto sul tasto on the baroque violin, as the bridge is often less curved than on a modern violin. Consequently, when the middle strings are pressed down with the left-hand fingers, the string that is being played is often so depressed that the bow cannot contact it in the vicinity of the left-hand fingers without first striking the strings on either side of them. One way of avoiding this issue on the modern violin involves depressing the strings on either side of the string being played in order to keep them clear of the bow. This is, however, not always possible on the baroque violin because of the aforementioned flatter bridge.
The following is an example of a G major scale played sul tasto on the baroque violin.
Video example 2.1 – G major scale sul tasto
The following is an example of a passage moving from molto sul tasto to ordinaire in Samuel Smith’s archive (2017a, p. 1).
Video example 2.2 – molto sul tasto transitioning to ordinaire passage in archive by Samuel Smith (2017a, p. 1), bar 1
Figure 2.1 – archive by Samuel Smith (2017a, p. 1), bar 1
Appearing above the intended passages, s.t. = sul tasto, m.s.t. = molto sul tasto, as in Figure 2.1 above.
 As the instruction sul tasto literally means to play with the bow “over” the fingerboard, the instruction is complicated on the baroque violin by the wide variation in fingerboard lengths on this instrument. Fingerboard length is relatively standard on modern violins; however, it has a much greater variation on baroque instruments, as it was not standardised in the 17th–18th centuries. Nevertheless, sul tasto may reasonably be interpreted as being an instruction to play with the bow at a distance far enough away from the bridge so as to alter the timbre, regardless of the length of the fingerboard.