"Angry man," wrote one student in 2010.

"He's the steriotypical [sic] music teacher.

But it's alleged the saxophonist - also known as Allan Yang - was no typical teacher.

Yang has been accused of being a repeated sexual predator, who for seven years preyed on underage girls.

The 51-year-old Kew man indicated on Wednesday he would plead guilty to 16 offences, which relate to a series of indecent assaults on four girls between 2006 and 2013.

At the time of his arrest, Yang had been working as a teacher and a professional saxophone player.

Scotch College has previously confirmed that Yang was a sessional teacher at the school from 2002 to 2009, a period that includes some of his sexual offending.

Yang, who appeared in court supported by a younger man, ran a business called the Melbourne Music Academy from his home in Kew from 2014 to 2015, according to ASIC records.

He was also the registered business owner of "Saxdragon" from 2003 until 2006, and his social media accounts continue to use that alias.

According to police documents tendered to the court, Yang's offending took place in Kew, where he touched, massaged and kissed young girls.

He is alleged to have laid one girl on a bed and removed her outer clothing; he is accused of touching the genitals of all four girls, either over or under their clothes.

Child sex abuse detectives launched an investigation into Yang last year, initially charging him with four counts of committing an indecent act with a child under 16.

Yang's own social media accounts promote his 2013 performance in Beijing as "the first-ever saxophonist to perform saxophone concerto with the Chinese National Symphony".

His Facebook accounts has dozens of photographs of him teaching, and performing with, students at various schools.

He lists himself as single, and as working at the Australian International Music Camp.

At the Melbourne Magistrates' Court on Wednesday, Yang's lawyer Shane Gardner indicated Yang would enter guilty pleas to all charges.

Police prosecutor Shane Wood told the court that Yang was not a flight risk, and Magistrate Luisa Bazzaniadjourned the matter for June 24 for a plea hearing.

With Steve Lillebuen

Note: an earlier version of this story said Yang had already entered guilty pleas to the charges. This was incorrect.