Composers will often ask for more extreme variations of ponticello and tasto techniques in order to get some quite interesting and evocative sound qualities and sound effects. Below are a few examples along with some practice tips.
Extremes of Ponticello
“Alto sul ponticello“, “molto sul ponticello“, “am Steg,” and “on the bridge,” are the various phrases that composers use to tell you that some or all of the bow hair is actually bowing on the bridge. This results in a noisy sound that is nearly if not completely free of the fundamental pitch. It is quite difficult to control this technique without a good deal of practice, as the bow can easily slip off the bridge in either direction, interrupting the sound conspicuously.
Start your practicing by first playing long bows on open strings, concentrating only on maintaining a very straight bow-stroke to keep the contact point absolutely steady. I suggest working in front of a mirror so that you can clearly see what is happening and how the contact point relates to the sound you’re producing.
After a while you’ll have a good handle on keeping the bow on the bridge, but adding some complexity to the process will challenge that ability. Try some of these small variations first
- increase and decrease the bow pressure
- increase and decrease the bow speed
- continuing with long bows, change strings mid-bow
- add easy left-hand patterns (scales, simple 1st-position patterns)
Once you’ve mastered the basics, head back to the Smooth Transitions page and use those examples to practice moving to and from this extreme contact point
Sometimes the composer indicates that he or she wants no pitch at all, just the woody sound of the bridge. This requires even more control over the positioning of the bow so that the strings do not vibrate. Notation for this technique varies and is usually specific to each composer.
I have found it easier to control the sound by angling the bow at least 45° to the bridge and drawing the bow along that new trajectory. This way you can bow the section of bridge that is between the strings without hitting the strings.
Finally, we can look at the well-used technique of sub-ponticello, which means to play on the strings between the bridge and the tailpiece. This yields a high-pitched, sometimes squeaky set of notes whose pitches depend on the geometry of your instrument. Since the pitch is not controlled, this is often used for texture or timbre. Again, notation is not standardized for this technique.
Extremes of Tasto
Playing “molto sul tasto” can produce a variety of sound timbres, depending greatly upon bow speed and pressure, and upon just how high up the fingerboard you go. Usually composers ask for this when they want a tone that is hoarse, covered, unfocused, woolly, weak, or flabby.
Challenges in playing molto sul tasto:
- The strings are closer together the higher up the fingerboard you travel, so you will need to work on isolating the string that you want.
- It is much easier to make the string’s vibration break down when bowing this far away from the bridge, so the factors of bow speed and pressure need sensitive treatment. (see the overpressure section for more on this)
- Depending on the geometry of your instrument, you may need to be careful when on the A-string so that you don’t scratch the shoulder of your cello with the tip of your bow.
Proceed to the final page in this section to see Ponticello and Tasto Examples from the Repertoire.