  The orchestra performance is full of sublime rich sounds. In particular, the
unison of violins sounds different from the solo violin. We try to clarify this
difference and similarity of unison and solo numerically analyzing the beat of
`violins` with timbre, vibrato, melody, and resonance. Characteristic
properties appear in the very low-frequency part in the power spectrum of the
wave amplitude squared. This ultra-buss richness (UBR) can be a new
characteristic of sound on top of the well-known pitch, loudness, and timbre,
although being inaudible directly. We find this UBR is always characterized by
a power-law at low-frequency with the index around -1 and appears everywhere in
music and thus being universal. Furthermore, we explore this power-law property
towards much smaller frequency regions and suggest possible relation to the 1/f
noise often found in music and many other fields in nature.
