Denobulan lullaby

From Memory Alpha, the free Star Trek reference

In 2154, Doctor Phlox offered to sing a Denobulan lullaby to Porthos, a dog that lived aboard Enterprise, during his attempt to lift Porthos' mood, since its owner, Jonathan Archer, was missing.

Phlox soon recalled that his singing would often drive his children to tears, and chose not to sing a Denobulan lullaby to Porthos. (ENT: "Storm Front")