CHICAGO has enjoyed hit singles in four decades and has sold more than 100 million albums. Whether you like Chicago or not, you cannot help but be impressed by the track record. The secret of Chicago's success seems to be the ability to write catchy pop songs, as well as provide entertaining live performances. ''At our concerts we want the audience to have a great time,'' said Jason Scheff, the bass guitarist. ''If you have a good song it will always work for you.'' The band was started in 1967 by six musicians with musical backgrounds ranging from classical through jazz to rock 'n' roll. They hit on a formula (a rock band with horns) and started writing songs which soon began topping the charts. As the Chicago Transit Authority, the band's debut album was released in 1969, but it was the second album where the band found real fame. The group toured with Janis Joplin and Jimi Hendrix and soon made chart history with hit singles such as Make Me Smile, Beginnings, Does Anyone Really Know What Time It Is and 25 Or 6 To 4. In the '70s the music direction changed from a fairly upbeat and soulful style to sweeter, more mid-tempo pop songs and ballads. IN THIS decade the band scored chart hits such as Feeling Stronger Every Day, If You Leave Me Now and Wishing You Were Here. Chicago overcame the accidental shooting death of guitarist Terry Kath to produce Chicago 16 and, in 1982, had a worldwide hit with Hard To Say I'm Sorry (US number 1). Chicago 17 became its all-time best seller. Hits like Stay the Night, You're the Inspiration and Along Comes a Woman propelled the album past the six million mark and reaffirmed the band's status as one of the most popular in the US. Over the years band members have had to be replaced but founders Robert Lamm and Walt Parazaider are still mainstays and the band's sound has remained distinctively Chicago. The most recent release, Chicago Twenty-1, is an album of catchy pop songs which dwell on the matters of the heart and wounded love. ''I guess we're matters-of-the-heart-type guys,'' said Scheff. ''Our inspiration for our songs comes from memories or sometimes something that happened that day. We want to write songs about real life. ''We don't just do love songs and ballads. Recently we've been trying to get more of an edge back on our songs, like on our first two or three albums. Something which has been missing on the last 15. If you listen to our recent albums we do more socially-conscious songs.'' THAT is not the case with Chicago Twenty-1, where only one song fits the bill; God Save The Queen. It is not a cover version of the British national anthem nor the Sex Pistols' version, but an original environmental protest song: ''God Save the Queen, Dear mother earth is dying away.'' The band has many influences, according to Scheff, but Elton John has had a great affect on its music. ''You can tell him when he comes to Hongkong I'm one of his biggest fans,'' Scheff enthused. It will be playing one concert in Hongkong as part of an Asia tour. Whether you're an old Chicago diehard or a recent convert, there will be something for you. ''We'll give you everything,'' said Scheff, talking about the coming show. Chicago is working on its next album, Chicago 22, due for a summer release. ''It's got a very cool, world sound,'' says Scheff. Chicago performs at 8 pm on Wednesday at the Hongkong Convention and Exhibition Centre. Doors open at 6 pm. Tickets at $420, $380 and $320 are available through the booking hotline, 529-7171 or from many Watson's branches.
