On the latest Billboard 200 albums chart (dated Jan. 21), The Weeknd’s Starboy returned to the top slot, earning a second week at No. 1. Meanwhile, in the top 10, four soundtracks populated the region – the first time that’s happened in more than 18 years.

The Billboard 200 chart ranks the week’s most popular albums based on their overall consumption. That overall unit figure combines pure album sales, track equivalent albums (TEA) and streaming equivalent albums (SEA).

Now, let’s take a closer look at some of the action on the latest Billboard 200 chart:

Original Broadway Cast Recording, Hamilton: An American Musical - No. 6: The original Broadway cast recording of Hamilton: An American Musical has now surpassed 1 million in U.S. album sales, according to Nielsen Music. The set sold another 16,000 copies in the week ending Jan. 5, which brings its total sales sum to 1.005 million since its release on Sept. 25, 2015.

Further, Hamilton is only the ninth cast recording to sell a million since Nielsen began electronically tracking music sales in 1991. The top selling cast album in Nielsen’s history is the highlights edition of the original London cast recording of The Phantom of the Opera, with 4.97 million sold. (The complete recording of The Phantom of the Opera — which is tracked and charts separately — has sold 503,000 since 1991.)

Aside from The Phantom of the Opera (Highlights) and Hamilton, here are the other million-selling cast albums of the Nielsen era: the original Broadway cast recordings of Wicked (2.67 million), Les Miserables (1.65 million), Jersey Boys (1.44 million), Rent (1.28 million) and The Lion King (1.04 million), along with the original cast recording of Mamma Mia! (1.71 million) and the highlights edition of the complete symphonic recording of Les Miserables (1.03 million).

James Arthur, Back From the Edge - No. 69 — As the singer’s song “Say You Won’t Let Go” breaks into the top 40 of the Billboard Hot 100 (rising 50-37 on the Jan. 21-dated chart), the tune’s parent album jumps into the top 100 of the Billboard 200 for the first time. It climbs 159-69 with 9,000 units (up 14 percent). Arthur won the ninth edition of the TV series The X Factor in the United Kingdom. Of the 13 winners of the U.K.’s The X Factor, he’s the second to notch a top 40 hit on the Hot 100, following Leona Lewis, who claimed three top 40-charting singles (including the No. 1 smash “Bleeding Love”).

Maren Morris, Hero - No. 67 — Four-time Grammy Award nominee Maren Morris bolts up the list, rising 131-67 with her major label debut album Hero (9,000 units; up 8 percent). Her single “80s Mercedes” drives 45-44 on the Radio Songs airplay chart (25.9 million in audience, in the week ending Jan. 8) and hits a new peak on the Hot Country Songs chart, rising 16-12.

Travis Scott, Birds in the Trap Sing McKnight - No. 19 — As the Billboard 200 adjusts back to business as usual after the busy holiday season, most albums on the chart see a decline in overall points earned in the past week. Only 10 albums on the list this week, that were also on the chart a week ago, see unit increases. Thus, even albums that have decreases in units — like Travis Scott’s album — can climb up the chart. Scott’s Bird in the Trap Sing McKnight eroded by 8 percent for the week (down to 20,000 units), but rises up the list 39-19.

Taylor Swift, 1989 - No. 88 — In the week ending Dec. 29, Taylor Swift’s 1989 album broke the 6 million threshold, and its sales (as of the week ending Jan. 5) now stand at 6.005 million. 1989 remains Swift’s second-biggest selling album, behind only Fearless, with 7.08 million. In total, Swift’s catalog of albums have sold 29.92 million.