Placido Domingo in hospital in Spain with pulmonary embolism The singer's representative, Nancy Seltzer, says doctors have asked the Spanish tenor and conductor to rest for three to four weeks, but that healing time varies. His return to the stage will depend on how quickly he regains his strength. Domingo returned to the stage just 45 days after undergoing colon cancer surgery in 2010 and has maintained a vigorous schedule and displayed an uncommon vitality at an age when most stars have stepped away from the spotlight. He is the most visible opera singer in the world and has performed more than 140 roles, expanding his repertoire to include baritone roles in the past half-decade. The Three Tenors member also recently was named the new goodwill ambassador for the U.N. Educational, Scientific and Cultural Organization for his efforts in spreading classical music around the world. Domingo has canceled his five performances in Daniel Catan's "Il Postino," which were to begin July 17 at the Teatro Real in Madrid, as well as an appearance on July 21 at Plaza Mayor.