The cello and its repertory have undergone radical transformations over the last seventy-five years. Whereas in former times musical styles and compositional conventions generally developed into an integral language over a period of some years, the proliferation of individual approaches to composition nowadays constantly challenges performers and their audiences to understand and assimilate new languages in rapid succession. Never before have instrumentalists been confronted with such difficulties as deciphering new notation for each different composer, mastering new technical requirements for each new piece, and transmitting often unnotatable sound-worlds convincingly to their audiences.
The left hand became liberated from its customary position-sense and the traditional diatonic framework, thanks to increased chromaticism, whole-tone, microtone and other scale patterns, glissandi and unusual non-consonant double- and multiple-stopping. Extreme applications of vibrato have been prescribed, including the ornamental vibrato-glissando, and traditional usages have been reversed, with demand for an intense, fast vibrato in soft passages, a wide, slow vibrato in loud passages, or even the use of senza vibrato for contrast or special effect. A wide variety of pizzicato effects has been developed, composers prescribing various pizzicato locations, specific plucking agents and other such instructions, and harmonics and scordatura have been exploited for their colouristic potential. Bowing technique developed in the twentieth century as a result of composers' demands on players to master awkward string-crossings, rapid changes and specific prescription of contact-point, speed and pressure, sudden or gradual changes in dynamic, often to extreme levels, and irregular slurrings and bow patterns.