Marc Anthony felt under pressure to not "screw up" his duet with Tony Bennett.
The 44-year-old star has collaborated with the multi-award winning singer for Tony's upcoming album.
Marc says producing the cover of For Once in My Life for the 86-year-old's Viva Duets record was a nerve-wracking experience.
"The difficult part is to actually stand next to him and not fall short," he revealed in an interview with ET Online. "You get to record with Mr. Bennett - don't screw it up. You feel more exposed than ever."
Tony has released duet material before, achieving huge success with Duets I and Duets II.
He has previously collaborated with a host of big name stars including Lady Gaga, Mariah Carey, Carrie Underwood and the late Amy Winehouse.
Tony has previously gushed about the former.
"I [think she has] the possibility of becoming the Picasso of music. She's very, very talented. She's different to any performer I've met during my whole career because she recreates herself on a daily basis. I can't believe her energy and her intelligence," he said about Gaga.
Viva Duets will be released worldwide on October 22.