The most direct manifestation of Tabuteau’s influence on string technique took place during his retirement. In the early sixties, Marc Mostovoy, a young American violinist-violist and conductor, traveled to Nice to study with Tabuteau. While a student at Temple University in Philadelphia, Mostovoy heard about Tabuteau’s musical concepts through one of his friends [Robert Rensch], a French horn player, who studied with Ward Fearn. Fearn had been a colleague of Tabuteau’s in the Philadelphia Orchestra for many years, and based his teaching on Tabuteau’s concepts. Mostovoy became fascinated with the musical concepts his friend was learning, and although he was a string player, began studying with Fearn himself.

Through Fearn, Mostovoy learned that the source of these ideas was Marcel Tabuteau. Mostovoy realized that in addition to its use in string playing, Tabuteau’s method had an obvious application in conducting and traveled to Nice to work directly with Tabuteau.

Mostovoy studied with Tabuteau for three summers. The first year, Tabuteau indoctrinated Mostovoy with all his basic concepts; the second year he elaborated and drove them home; for the third he applied his principles to music of the masters. In addition to playing at his lessons and taking notes, Mostovoy analyzed scores with Tabuteau. At first, Tabuteau acted as a coach. Mostovoy played and Tabuteau would comment and demonstrate.

After some time passed however, they also began talking about directly applying Tabuteau’s concepts to specific aspects of string playing. For example, Mostovoy began to realize that conventional string fingerings seemed to be at odds with the phrasing principles Tabuteau was teaching, so he started experimenting with fingerings that would better match Tabuteau’s musical ideals.

Tabuteau and Mostovoy began working on both left and right hand technique in greater detail. Some aspects of string technique covered by Tabuteau and Mostovoy included changing positions, string crossings, bow distribution, and vibrato. Some simple examples follow:

Changing position: They determined that shifting, like breathing, must be done where it makes the most sense musically—with the phrasing or note groupings, and not where it is simply convenient or where it falls best in the hand. In a passage of dotted figures, for example, shifting after a short note produces a disturbance in the line. Tabuteau, therefore, would advocate shifting after one of the dotted notes. In addition to considering when to shift, the player must also decide how to shift. There are many kinds of shifts at a string player’s disposal. Different shifts are appropriate in different styles of music. There are many considerations. The underlying principal is this: The music always determines the technique and not vice versa.

Changing strings: String crossings, like shifting, can be done either for convenience or for musical reasons. Each string and each position on the string has a unique color. This must be considered when deciding whether to change strings or change position and, of course, where to do it.

Vibrato: Tabuteau felt that vibrato had to come from within the note rather than being superimposed on the note. The player should not have a “one-size-fits-all” vibrato that is applied automatically; rather, vibrato must be in proportion to both the style of the music and the placement of each note within the phrase. Its aim is to ornament and enhance the musical line. Music written during the Classical and Baroque periods, for example, generally requires a smaller, more compact vibrato than music written in the Romantic era. Vibrato can also be a factor in determining the intensity of sound. A faster vibrato creates a sound with more intensity than a slower vibrato.

Bow distribution and placement: Tabuteau used string bowings to illustrate his system of numbers. A progression of numbers is not exactly a crescendo or diminuendo. It is rather a scaling of color. To understand this point, think of the bowing distribution on the violin—in the space between the fingerboard and bridge. With the oboe, the speed of wind and the position of the reed on the lips, are equivalent to the potential on the violin for producing tone color, i.e. the physical life of the notes. Tone color isn’t a static quality; it has energy. Scaling the color is one of the elements that creates units of motion—the life of the music.

Tabuteau used his number system to indicate color among other things. Mostovoy thought that since string players use numbers to indicate fingering, it would be confusing to use numbers elsewhere. Through his work with Tabuteau, Mostovoy translated Tabuteau’s numbers into a set of markings for string players. Mostovoy called these markings his “hieroglyphics.” Some examples include a squiggle for a certain kind of intensity; an arrow pointing up for a lift or ahead for forward motion; a circular loop figure for a certain nuance (loop-de-loop); the letter ‘M’ for a dynamic between mezzo-forte and mezzo-piano, and so forth.