Nothing like a No. 1 single to give an album a boost. Just ask reggae-rockers UB40, whose Promises and Lies enters at a solid No. 7 thanks to ''Can't Help Falling in Love.'' More surprising is the No. 10 debut of Chicago's droney- guitar rockers Smashing Pumpkins, who, until now, have been very much an underground phenomenon. Their first album, Gish, originally an indie release, created a major buzz and sold a very respectable 400,000 copies. ''This has been an old-fashioned success,'' says a spokesperson for Virgin, the Pumpkins' label. ''They've evolved organically into a big thing.'' Of course-how else would pumpkins grow? pop albums Last Weeks on Week Pop Albums Chart

1 1 Cypress Hill Black Sunday, Ruffhouse/Columbia 2 2 3 Soundtrack Sleepless in Seattle, Epic Soundtrax 6 3 2 U2 Zooropa, Island/PLG 4 4 4 Janet Jackson janet., Virgin 11 5 6 Stone Temple Pilots Core, Atlantic/AG 32 6 5 Barbra Streisand Back to Broadway, Columbia 5 7 - UB40 Promises and Lies, Virgin 1 8 8 Soundtrack The Bodyguard, Arista 37 9 7 Rod Stewart Unplugged and Seated, Warner Bros. 10 10 - Smashing Pumpkins Siamese Dream, Virgin 1

Country Albums

1 3 Alan Jackson A Lot About Livin' 43 (And a Little 'Bout Love), Arista 2 1 Billy Ray Cyrus It Won't Be the Last, 6 Mercury Nashville 3 2 Clint Black No Time to Kill, RCA 3 4 4 George Strait Pure Country (soundtrack), MCA 46 5 5 Wynonna Tell Me Why, Curb/MCA 12 6 7 John Michael Montgomery Life's a Dance, Atlantic 38 7 5 Billy Ray Cyrus Some Gave All, Mercury Nashville 63 8 8 Brooks & Dunn Hard Workin' Man, Arista 23 9 9 Reba McEntire It's Your Call, MCA 33 10 10 Dwight Yoakam This Time, Reprise 19

Music Videos

1 1 Smooth ''You Been Played,'' Jive Records 11 2 3 95 South ''Whoot, There It Is,'' Ichiban Records 11 3 2 Ice Cube ''Check Yo Self,'' Priority Records 6 4 13 Luke ''Work It Out,'' Luke Records 9 5 11 2pac ''I Get Around,'' Interscope/Atlantic 17 6 41 SWV ''Right Here,'' RCA Records 2 7 6 Duice ''Dazzey Duks,'' Bellmark Records 11 8 9 Kris Kross ''Alright,'' Ruffhouse/Columbia 4 9 20 Cypress Hill ''Insane in the Brain,'' 7 10 4 Luke ''Cowards in Compton,'' Luke Records 6 c 1993 BPI Communication Inc./ Soundscan Inc. used with permission from Billboard, Aug.14,1993

c 1993 Video Jukebox Network, Inc. used with permission for week ending July 30,1993