The harmonic melody rings out on a Friday evening. 'I'm lucky I'm in love with my best friend, lucky to have been where I have been, lucky to be coming home again. Ooh ooh ooh ...'
It isn't the Jason Mraz hit single Lucky blasted from an amplifier. Rather, it is a refreshing remix sung by 10 a capella singers gathered in a living room, accompanied by imitated sounds of guitar plucking and drums.
They can't afford a proper recording studio or sound engineer. They practise at home every Friday evening and teach each other.
The group that calls itself Songbird made its debut in the summer of 2009, and then undertook some public shows in shopping malls and universities.
And earlier this year they made it to the stage for the second time at Sheung Wan Civic Centre Theatre.
Their concert, entitled Little Bits of Love, was a rich collection of English hits, from Happy Ending to Way Back into Love, and Canto-pop tunes sung by local singers like Eason Chan Yik-shun and Kay Tse On-kei.
'It's been a great lesson for us,' says Dominic Lam Ho-yan, a 19-year-old music major at Chinese University, better known as Beep Beep to his mates. 'Because of limited resources, we were not only singers and songwriters, but also producers, dancers, soundmen, light engineers and costume designers.'
The 10 ex-members of the Hong Kong Children's Choir formed the group about three years ago, when they were performing at the 50th wedding anniversary of one of the member's grandparents. They were all nearing 18, and about to leave the children's choir.
As they were saying goodbye, one said: 'It isn't a bad idea to sing like this as a small group. We all love singing, and this way we can still keep in touch.'
So Songbird was born. However, they realised that forming a group was not as easy as they had imagined. 'Even coming up with a practice time for us all is a headache,' says Vivian Suen Ming-wai, 21, a mezzo-soprano. 'All of us have very different schedules.'
In the end, they decided on a fixed time, 7-9pm every Friday.
Like every successful band and choir, Songbird is anxious to establish its own distinct style. The group has been actively experimenting with new possibilities by tapping each member's talents. 'Two of the guys in the team - Matthew [Lam Ho-yan] and Poze [Wong Hung-pok] - are our beatboxers, who best imitate a percussion band', says Charmaine Chow Yan-wing, jokingly pointing to her friends. 'She's [Kitty Cheung Ka-yan] a real erhu and the rest contribute to producing new medleys based on Canto-pop, which we believe is a new trend compared with the more established foreign a capella groups.'
Looking ahead, Songbird is keen to promote a capella to a wider audience. Its big dream is to one day perform in the prestigious Hong Kong Coliseum.