The soundtrack takes over the lead on the Billboard 200 album chart. It also logs its fourth week at No. 1 on Top Soundtracks, its second week ruling Top Digital Albums and moves from No. 5 to No. 1 on Top Internet Albums.

Meanwhile, the original repertoire that inspired the musical locks its fourth straight week at No. 1 on Top Pop Catalog Albums. Sealing the Swedish group's monopoly, the original cast recording from the stage production rules Top Cast Albums for a third straight week. In short, ABBA songs dominate almost every album chart.

REELING IN THE YEARS

Following the triumph of the Juno soundtrack in February, this marks the second time in 2008 that a feature film's audio souvenir leads the Billboard 200. That might not sound like a rare feat, but not since 1998 have two film soundtracks taken charge of the album chart within a calendar year. And 1998 was a landmark year for soundtrack sales.

In the first sales week of 2003, the soundtrack to Eminem's 8 Mile registered the last of its four weeks at No. 1. The July release of that year's Bad Boys II also led the Billboard 200, but the former had been a carryover from the prior year.

No other film soundtrack led the chart until Jack Johnson's Curious George album in February 2006. That was the first of six soundtracks that would reach No. 1 through the end of 2007, but four of those were from Disney Channel projects, Dreamgirls being the only other chart-topping album from a theatrical release within that span.

You need to drift back 10 years to find the last occasion when two or more film soundtracks started Billboard 200 reigns in the same year: Titanic (16 weeks at No. 1, 16-times platinum), City of Angels (three weeks, five times platinum) and Armageddon (two weeks, four-times platinum).

With 62.7 million film and TV albums sold in 12 months, 1998 was the fattest soundtrack year in Nielsen SoundScan history. Even if Titanic had been subtracted from that haul, the remaining 53.4 million copies of soundtrack sales would still have netted the category's best year.

Soundtrack numbers cooled sooner and more drastically than overall album volume, but thanks in large part to Disney Channel's High School Musical franchise and the Hannah Montana series, that market segment has improved in recent years.

Soundtracks swelled by 18.9 per cent in 2006, to 27.2 million. There was a 9.6 per cent decline last year, but so far in 2008, the 12.3 million copies tracked through the week ending August 10 mark an 11 per cent improvement over the same span of 2007.