The Perfect Emancipation Concert featured members of the Aum Shinri Kyo cult singing songs composed by their spiritual leader Shoko Asahara, who is in jail pending trial for the sarin gas attack in which 12 people died and more than 5,000 were injured.
"His supreme vibration, profound doctrine and esoteric teachings are condensed in each song so that everyone can understand it," according to the Aum Shinri Kyo website.
But Japanese police fear that the group could once again engage in violent activity as its members prepare for Armageddon - due in early September this year, according to Shoko Asahara.
An investigation by the Public Security Investigation Agency in December found the group, with a membership estimated at 1,500, was seeking to expand its membership and raise funds.
Its assets include a group of discount computer outlets whose sales amount to $34m a year.
'God's sexual love'
A glance at the website shows the importance of music to the Aum cult members.
Apart from the "Master's" songs, sound clips on the site demonstrate Astral Music ("pure melodies that Master Asahara has brought back from the higher Astral world") and Symphonic Music with titles such as "Gods' sexual love" and "Creation of the gross world".
But the music at Sunday's concert, sung by a trio of young women dressed in candy-coloured saris, was less tuneful than the versions on the Internet. Not outlawed
Aum Shinri Kyo operates legally in Japan.
The government decided the cult itself was not a threat, despite individual members being linked to criminal activity.
Shoko Asahara has pleaded not guilty to involvement in the gas attack.
But the cult lost its legal status and tax privileges as a religious organisation after some of its top members were arrested in the aftermath of the gas attack.
The sect is also blamed for another attack in the central Japanese city of Matsumoto in 1994, which left seven people dead.
Devotees insist that these days the group is intent on nothing more than disseminating its religious beliefs.