In addition, the AP independently verified that the women worked where they said they did and that Domingo overlapped with them at those locations.
Plácido Domingo is one of the most celebrated and powerful men in opera. He is General Director of Los Angeles Opera and his worldwide Operaliacompetition has identified some of the world's finest opera singers.
Domingo told the AP that the allegations were "deeply troubling and, as presented, inaccurate", adding, "I believed that all of my interactions and relationships were always welcomed and consensual".
"I'm stepping forward because I hope that it can help other women come forward, or be strong enough to say no", she said.
Patricia Wulf, who sang with Domingo at the Washington Opera, was the only one of the nine to go on the record, and said she was uncomfortable by his asking her each and every night if she had to go home after work, and by his trying to enter her dressing room uninvited.
The San Francisco Opera said it would scrub a sold-out October 6 concert featuring Domingo, which had been to mark his 50th anniversary with the company. His most recent album is Volver, a recording with guitarist Pablo Sáinz-Villegas, which was released by Sony Masterworks in 2018.
In a joint statement to AP, the institutions said the allegations against Domingo predated the merger.
On Tuesday morning, the Philadelphia Orchestra announced that it had rescinded its invitation for Domingo to sing at its season-opening gala, saying: "The Philadelphia Orchestra Association has withdrawn its invitation to Plácido Domingo to appear as part of its opening night concert on September 18, 2019".
The orchestra justified its decision by saying that it is "committed to providing a safe, supportive, respectful and appropriate environment" for its staff, collaborating artists and its audience. The orchestra said that it will announce a replacement soloist and program at a later time.
One of the women said the multiple Grammy award victor stuck his hand down her skirt and three others said he forced wet kisses on their lips - in a dressing room, a hotel room and at a lunch meeting.
And the Washington National Opera, where Domingo has served as a top manager for 15 years, said in a statement it has "zero tolerance policies" regarding harassment of any kind. Women were warned not to be alone in an elevator with him.
None of the women could offer documentation, such as phone messages, but AP spoke to many colleagues and friends that they confided in.
Eventually, she reluctantly agreed, saying: "I wasn't going to have an opera career if I didn't give in".
The woman said he then led her to a bedroom where he took her clothes off, then undressed himself.
Seven women said they felt their careers had been hurt after refusing Domingo's advances.
Only one of the nine women would allow her name to be used - Patricia Wulf, a mezzo-soprano who sang with Domingo at the Washington Opera.
Domingo has denied the accusations, but noted: "Still, it is painful to hear that I may have upset anyone or made them feel uncomfortable".
In an acknowledgement that the #MeToo movement has shifted expectations for men in positions of power he added, "I recognize that the rules and standards by which we are - and should be - measured against today are very different than they were in the past". It was promoted as a "special one performance-only event" with "one of the most influential singing actors in the history of opera" and was one of several gala events this year to celebrate his legendary career.