The song "O Tannenbaum" features a lead vocal by Johnny Mathis.

Entity and relation annotations:
id: 0
type: entity
value: text: "O Tannenbaum"
labels: <Work_of_art>
id: 1
type: entity
value: text: Johnny Mathis
labels: <Person>
type: relation
to_id: 0
labels: Person:performs:Work_of_art
from_id: 1