Two4 (1991)

This one comes in two versions: it's scored for either violin and piano or violin and shō, a Japanese instrument that sounds somewhat like a cross between an organ and a harmonica. Cage was rather enchanted with the shō when he discovered it late in his life, so he wrote a few pieces for it. I'm not sure why he gave the option of either piano or shō for Two4. They certainly don't sound anything alike.

Cage's score exploits the different abilities of the three instruments in two interesting ways. First, as a violin, unlike a piano/shō, can sustain a note indefinitely, the violin holds long drones of single notes while the piano/shō plays more quickly (though still fairly slowly - just a few notes per minute, in fact) over it. Second, while the pitches available to a piano/shō are discrete and fixed, a violin has the whole field of pitch in its range at its disposal. Hence the violin part is microtonal: Cage splits the octave into eighty-four notes (versus the standard twelve). I must confess, though, that my untrained ear would never have picked up on this had I not read about it. I can sometimes tell when music is microtonal - it's obvious in Harry Partch and a lot of world music, for example - but frankly I can't tell what difference it makes here.

Obviously, the two versions sound fairly different, and each has its benefits and drawbacks. On the one hand, the shō has a rich, unusual timbre that brings a rather more exotic flavour to the piece, and its notes can be sustained for as long as the player's breath so it tends to be quite droney like the violin. They merge together; it's sometimes difficult to tell where one instrument begins and the other ends. However, partly for this reason, the shō tends to drown out the subtleties of the violin part. The piano isn't so invasive. Since the violin is played so softly and without vibrato, we have a chance to focus on the slight "imperfections" in the drones, that are like ripples on the surface of water. It provides an intricate and beautiful bed of sound to complement the delicate piano notes.

Piano or shō, I love this piece. I love its long drones and its gradually changing texture as over time, almost imperceptibly, the pitch of the violin drops. It slowly divides the two instruments, since the piano/shō part is for the same seventeen notes throughout. Both begin at a high pitch, but the violin ever so slowly drifts away.