THREE bands had played, the rain began, and last Sunday's preliminary round of the 9th Carlsberg Pop Music Festival came to an untimely end. But fear not, the festival will return to Kowloon Park on August 15 for another try at sorting out the wonderful, the not-so-wonderful and the wonderfully wacky among 39 amateur bands. Produced by Tom Lee Music and sponsored by Carlsberg, the festival culminates in a September 4 battle of 12 bands. As usual, this year's festival offers a healthy share of hard rock, a favourite style with young musicians in Hongkong. In fact, all three of the pre-deluge participants on Sunday - Septuple, Private Pills and Evolution - fell into this category. Exactly what we can expect from some of the other bands, notably Jackal's Dream, Black Box & The Dog, and Rotten, remains to be heard. Don't miss them, though, because these less-than-poppy bands tend to be weeded out in the preliminary round. IT SHOULD be sm oother sailing from now on for Mothership. At a meeting on Tuesday night, the 10 members of Hongkong's hottest club band chose David McDowell to be their manager - a decision long overdue. With a single person at the helm of the Mothership's business dealings, the group should be able to focus more on what they do best: play good music. ''My role is administering the band and arranging the details of the gigs they are going to play, as well as the promotion,'' said McDowell, a designer. ''But the band will continue to be involved in managing themselves in many respects. The reason for that is that they have a very strong team spirit - in how they play their music and in how they entertain their audiences.'' Mothership appear at Radio Free Hongkong at Westworld on July 29 and at the Rebirth of Cool at the Viceroy of India on July 31. After that, the band will be on hiatus until September. A WHOLE new world has been opened up for music-lovers. Yesterday, the Cantonese version of the Aladdin film soundtrack was released. Singers Sarah Chen and Emil Chou were picked to do the honours by the Walt Disney Company. The Taiwanese Chen certainly should be familiar to Hongkong ears as she was the voice behind The Beauty and the Beast soundtrack in which she performed a duet withsuperstar Jackie Chan. Chou, a Hongkong-born singer-songwriter with nine albums under his belt, contributed his vocals to the Mandarin version of the song A Whole New World as well. The English version of the song, which features singers Peabo Bryson and Regina Belle, took number one on the RTHK charts when it was released in March and also received an Oscar for Best Original Song. The film's soundtrack was awarded Best Original Score. SEVEN movies are being shown in the Canadian Film Week (starting Wednesday), including Jean Beaudry's The Clean Machine starring Vincent Bolduc, Delphine Pipemi and Pierre-Luc Brillian. A comedy about two boys who pursue their success in business with radically different management styles, the film won the gold medal at Salerno's 22nd Giffoni Film Festival for the Young in 1992. The Clean Machine is the opening film for the Canadian film festival and will be repeated again on July 24. Among the other films showing are four English-language films including The Flying Sneaker, Joshua Then and Now, 90 Days, and Animation. The Revolving Doors is in French and La Sarasine is in French and Italian. Both have English subtitles. For details, call 734-2925.