The performer had to postpone his original tour date in Fresno back in December because of bruised vocal cords.
According to the LA Times, his voice is still damaged.
During his concert in Los Angeles on Sunday, the newspaper reports he sang the first half of the line, then let his backup vocalists or even the audience take over.
Tickets are still available for tonight's concert at the box office and on Ticketmaster.
Doors open at 6 p.m.
The concert is scheduled to begin at 7:30 p.m.