'The songs still connect to the era and society of today. Is it because the songs are really well written?' He laughs. 'Or is it because society hasn't changed and things continue to repeat, so that the songs fit in with the current era?'

Tat Ming Pair's most distinctive songs - such as first hit, Romance of the Stone - combine Chinese instrumentation with synthesisers and guitars. A prime example is Tonight the Stars are Bright, which begins with a few notes that wouldn't sound out of place in a Cantonese opera, but quickly transforms into an electronic melody with a rock edge. A minute and a half into the song, just before the chorus hits, the listener hears the guitars for the first time.

Their sound remains the same, but a lot has changed since Tat Ming Pair disbanded in 1990, although there have been rare reunions for special occasions, such as the gig in 2004.

'At the time we split, we were at our peak,' Wong says. 'We didn't feel we'd be able to top what we'd done, either on the creative side or the business side. We had also held our first big stadium concert. We felt there was nothing more we could do, and decided to spend time apart and explore other avenues of making music.'

Over the following two decades, Wong established himself as a solo performer and founded People Mountain People Sea in 1999. Lau composed film music, winning accolades for his score for Clara Law's Temptation of a Monk. He also became an actor - best known for his roles in Stephen Chow Sing-chi films such as The God of Cookery and Forbidden City Cop - and most recently appeared in the 2010 Barbara Wong film Perfect Wedding.

While Wong and Lau each found success after Tat Ming Pair, both felt the draw to reunite for the concert series at the Coliseum on April 20-23. 'The decision to hold the reunion shows was simple,' Wong says. 'It's roughly the 25th anniversary of the band, and we wanted to stage a tribute of some sort. Of course, we had a lot of people by our side, encouraging us: the record company, the concert promoter. But the most important factor was the fans, who had been hoping we'd put on a show for them. As we hadn't put on a concert in years, we decided to do it for the fans, for ourselves and to fulfil a matter of the heart.'

But by the middle of last month, the pair hadn't started rehearsing together. 'We have just been preparing on our own in our homes and in our studios,' Wong says, adding he had started an exercise programme to build the stamina to sing for an entire stadium show. When asked how he feels about this reunion, he takes a moment before answering. 'There's a feeling that we're strangers and very intimate at the same time, because ... it's been four or five years since we last met. During that time we ran into each other a few times, but we haven't kept in close contact.

'Last year, when the record company and promoters were contacting us, we got in touch again. I feel that we have both changed, but that we still know each other well. It's been more than 20 years, but we haven't become completely different people. When we're playing music together - for promotional spots on television or rehearsing - there's a tacit understanding between us. There's also a sense of happiness because we're really proud of these songs.'

In honour of the upcoming reunion, Tat Ming Pair have revisited a track - based on the '60s pop hit Song of Movie Stars - that the band first recorded in 1990 and then re-released in 2004. 'During that era there was a Cantonese film star named Cheng Kwan-min who sang the song, which uses the names of movie stars for its lyrics.' The Tat Ming Pair versions use the names of celebrities, as well as social and political figures, from their respective eras. 'We felt we should shuffle the deck and deal the cards again. So we did a new version.'

The 2012 track name-drops the likes of Deanie Ip, Nicholas Tse, Cecilia Cheung, Ma Ying-jeou, Henry Tang, Steve Jobs and Michelle Obama. Nicholas' father, Patrick Tse, was one of the actors named in the original. The song also mentions the chief executive election, and adopts recent slang derived from video game culture. In short, the song is very much a product of this era, and also works as a clever commentary on Hong Kong society and culture.

A second new single is slated for release closer to the concert dates, but is yet to be recorded. Lau is Tat Ming Pair's primary songwriter, and the upcoming song is one of his compositions. 'He has written more songs than me, and he has written better songs than me,' Wong says. 'Plus, he plays instruments. My primary role has always been to sing.'

Regarding the state of contemporary music in Hong Kong, Wong says: 'I don't agree that there's nothing new going on. If we're just looking at popular music, it's not going to be particularly innovative regardless of the country. It's going to be conservative. It's always going to be up to the alternative scenes to give life to popular music, whether you're in Europe, the United States, Hong Kong or China. Hong Kong's mainstream music isn't as uninteresting as everyone thinks. I encourage people to listen to our city's indie artists.'

Recently, Wong has been listening to the latest albums by Bon Iver, James Blake and Leonard Cohen. 'Cohen is nearing 80 and is a role model for me. He's still releasing new material and still has the power to move people.'

Wong, 49, hopes for similar longevity and to keep recording for as long as he is able. 'I don't have any plans to stop singing, and look forward to growing old. I often wonder who my audience will be then and what my voice will be like. It's not fashionable to be old in Asia - where youth is so celebrated - but I want to help change that attitude.'

Tat Ming Pair, 8pm, April 20-23, Coliseum, Hung Hom, HK$180-HK$480, Urbtix. Inquiries: 2111 5999