UK
27 January 2015
Last updated at 12:05 ET
Describing the time at the height of his fame, he said claims fans were allowed backstage after his gigs were untrue as he did not want people to find out about his "secret" wig.
Mr Gadd denies 10 offences allegedly committed between 1975 and 1980.
Giving evidence in the witness box at Southwark Crown Court, he said it had been difficult to recall the dates being referred to in the case.
He said he had used his autobiography to "charge my memory".
Asked by defence barrister Sallie Bennett-Jenkins QC at the start of his evidence whether he had sexually assaulted any of the woman who have accused him, Mr Gadd replied: "No I did not."
He told the court started to lose his hair at the age of 18, and had been wearing a wig since 1965 because "rock 'n' roll singers had to have hair".
"I was hoping that nobody knew about this," he said, adding that after performances he would rush back to his hotel suite to clean and maintain his hairpiece before putting it back on and going to sleep.
He added: "I never had anybody backstage after a performance, because this was a major problem in my life, or rather a major chore. I had to deal with it."
'Glitter-mania' Mr Gadd is accused of attempting to rape and indecently assaulting a girl under the age of 13 in 1975.
He is also charged with four counts of indecent assault on a fan in 1977 at hotels in Leicester and Birmingham when she was aged 12 and 13; plying the same girl with alcohol, and having unlawful sexual intercourse with her.
Mr Gadd was taken through the evidence by his lawyer, Sallie Bennett-Jenkins QC
Two further charges allege he indecently assaulted a girl of 13
on a date between October 1979 and December 1980, in his dressing room
at a venue in Watford where he was performing.
But, taken through the allegations by Ms Bennett-Jenkins, Mr Gadd denied all the claims made by the three woman.
Mr Gadd, who confirmed he had pleaded guilty to possession of images of children in 1999, told the court he had a history of long-term relationships with adult women.
He said during the 1990s he was taking amphetamines, compounded by the fact that he was away from the mother of his second son, Gary Jnr.
Earlier, he told the court how, influenced by Elvis Presley, he started his career under the name Paul Raven, before creating the Ivor Novello Award-winning act of Gary Glitter.
Mr Gadd gave the jury a demonstration of the musical sound of his hit single Rock And Roll, and talked about how "absolute Glitter-mania" broke out after his hit 1973 record Do You Wanna Touch Me.
"It was like 20,000 people at the airport in Melbourne screaming. Nobody could ever hear a concert, including me. Because they would just scream and scream and scream," he told the court.
But by 1977 his popularity was fading, and he was declared bankrupt, a situation Mr Gadd told the court he put down to the high UK tax rate at the time and mismanagement by his business managers.
Talking about his fans, he said that to this day he is asked for keepsakes.
"I feel like I want to give them anything because they have given me such a great life," he told the court.
The trial was adjourned until Wednesday.
by Emily Straton and Biodun Iginla, BBC News, London
Former rock star Gary Glitter has told a jury he did not carry out sexual assaults on three girls in the 1970s.
The 70-year-old - charged under his real name, Paul Gadd - has been giving evidence at Southwark Crown Court.Describing the time at the height of his fame, he said claims fans were allowed backstage after his gigs were untrue as he did not want people to find out about his "secret" wig.
Mr Gadd denies 10 offences allegedly committed between 1975 and 1980.
Giving evidence in the witness box at Southwark Crown Court, he said it had been difficult to recall the dates being referred to in the case.
He said he had used his autobiography to "charge my memory".
Asked by defence barrister Sallie Bennett-Jenkins QC at the start of his evidence whether he had sexually assaulted any of the woman who have accused him, Mr Gadd replied: "No I did not."
He told the court started to lose his hair at the age of 18, and had been wearing a wig since 1965 because "rock 'n' roll singers had to have hair".
"I was hoping that nobody knew about this," he said, adding that after performances he would rush back to his hotel suite to clean and maintain his hairpiece before putting it back on and going to sleep.
He added: "I never had anybody backstage after a performance, because this was a major problem in my life, or rather a major chore. I had to deal with it."
'Glitter-mania' Mr Gadd is accused of attempting to rape and indecently assaulting a girl under the age of 13 in 1975.
He is also charged with four counts of indecent assault on a fan in 1977 at hotels in Leicester and Birmingham when she was aged 12 and 13; plying the same girl with alcohol, and having unlawful sexual intercourse with her.
Mr Gadd was taken through the evidence by his lawyer, Sallie Bennett-Jenkins QC
But, taken through the allegations by Ms Bennett-Jenkins, Mr Gadd denied all the claims made by the three woman.
Mr Gadd, who confirmed he had pleaded guilty to possession of images of children in 1999, told the court he had a history of long-term relationships with adult women.
He said during the 1990s he was taking amphetamines, compounded by the fact that he was away from the mother of his second son, Gary Jnr.
Earlier, he told the court how, influenced by Elvis Presley, he started his career under the name Paul Raven, before creating the Ivor Novello Award-winning act of Gary Glitter.
Mr Gadd gave the jury a demonstration of the musical sound of his hit single Rock And Roll, and talked about how "absolute Glitter-mania" broke out after his hit 1973 record Do You Wanna Touch Me.
"It was like 20,000 people at the airport in Melbourne screaming. Nobody could ever hear a concert, including me. Because they would just scream and scream and scream," he told the court.
But by 1977 his popularity was fading, and he was declared bankrupt, a situation Mr Gadd told the court he put down to the high UK tax rate at the time and mismanagement by his business managers.
Talking about his fans, he said that to this day he is asked for keepsakes.
"I feel like I want to give them anything because they have given me such a great life," he told the court.
The trial was adjourned until Wednesday.
