Federal agents arrested the head of a Queens music school today on charges that he paid for sex with children, and tried to buy sex with girls as young as 8.

Oliver Sohngen, director of the Long Island City Academy of Music, faces eight felony counts of sex trafficking, sex trafficking conspiracy, and attempted sex trafficking.

In a criminal complaint, investigators said that the arrest of an unnamed pimp in November 2013 led them to Sohngen, listed in the pimp's phone under the alias Helmuth Moss. The feds say they talked to three of the pimp's underage victims, one 15 and two 17, and established that he had paid for sex with each of them at the pimp's apartment on Davidson Avenue in the Bronx in 2013.

Also in 2013, over the course of three months and several lengthy text threads, Sohngen and the pimp allegedly tried to arrange for Sohngen to have sex with several girls, including an 8-year-old and an 11-year-old.

In one stomach-turning exchange about sex with the 8-year-old and a 13-year-old, according to the complaint the pimp wrote, "Can you look up a hotel"

Sohngen allegedly responded, "I know a hotel but she needs to dress"

The pimp: "Dress how."

Sohngen: "Old"

Later in the same discussion, the pimp wrote, "When your done. Can you drop them off at chuck e cheese. That where the family thinks they are going."

"Which chucks chs?" Sohngen allegedly replied.

Each alleged arrangement for sex with the younger girls fell apart, according to prosecutors. The pimp describes a 16-year-old friend of the girls as a go-between who helped shuttle them away for sexual abuse.

The phones used for the texts allegedly traced back to Sohngen, and one was allegedly the number he lists for people to call the music school. His final undoing seems to have been a series of Craigslist ads seeking "casual encounters" for some unspecified type of sexual fetish. An NYPD officer responded to one of the ads in late 2015, posing as a 15-year-old girl, according to the complaint.

After initiating contact, the undercover wrote at one point, "Sorry I couldn’t get back on my computer yesterday. I have soccer practice almost every day now. Not on Monday tho. I can see you after school if you are around. You didn’t say how young you like btw. I like older, just want to make sure you like younger :)."

Sohngen allegedly responded, "I can’t answer that in writing. Lets agree ure 18…"

The undercover replied, "Umm haha ok, Im 15. But you want me to say 18. Got it wink wink. So u around Monday."

Sohngen allegedly wrote, "This sounds like entrapment by police..."

Still, he allegedly kept up contact through January 2016, and tried to arrange to meet the "girl" for sex.

Sohngen is from Germany and moved to the United States in 1990, studying music in Cleveland. He told the Huffington Post that he moved to New York to pursue opera, and wound up teaching music to support himself. He founded the Academy in 2010.

“It’s so shocking for us. Of course it’s heartbreaking too,” Shera Sunico, a coffee shop worker who regularly serves Sohngen, told CBS2. “Oliver is a really happy person. Whenever he comes here he talks to us, he sings. He’s a jolly person actually.”

Sohngen has a son and a daughter, and children feature prominently in his school's promotional materials.

No one returned a message left on the Academy and Sohngen's phone, nor did anyone respond to an email to the Academy. Sohngen is expected to be arraigned this afternoon. Attorney information for him was not yet available at press time.