Because
type: WorkPerformance
baritone: http://data.carnegiehall.org/names/33013
piano: http://data.carnegiehall.org/names/65896
performer: http://data.carnegiehall.org/names/33013
performer: http://data.carnegiehall.org/names/65896
work performed: http://data.carnegiehall.org/works/24098