Keith Urban banks his 21st No. 1 on Billboard's Country Airplay chart (dated Jan. 14), as "Blue Ain't Your Color" climbs 2-1 in its 20th week, increasing by 18 percent to 44.8 million audience impressions in the week ending Jan. 1, according to Nielsen Music.

Written by Steven Lee Olsen, Hillary Lindsey and Clint Lagerberg, the retro sound of "Blue" is a departure from most of Urban's past hits. "Despite the waltz time signature, I feel it is more of a soul song," Urban tells Billboard. "We worked for a long time in the studio to get the feel and simplicity to where it is. Certainly when [parent album] Ripcord came out [in May], it was definitely one of the tracks that people responded to immediately. Even when we kicked off the tour [in June], it was getting the same reaction live. I loved it the first time I heard it [and] I love playing it live, so it's really the best feeling when it connects the way that this one has."

As "Blue" rules Country Airplay, it also paces both Hot Country Songs (which combines airplay, sales and streaming data) and Country Digital Song Sales for a ninth week each. The track leads the latter list with an 88 percent surge to 48,000 downloads sold in the week ending Dec. 29, 2016 (a frame bolstered by holiday shopping). Since its release, "Blue" has shifted 651,000 downloads to date.

On Country Streaming Songs, "Blue" holds at No. 6 (4.2 million U.S. streams, essentially even week over week) following a three-week run at No. 1 in November and December 2016.

Urban's simultaneous command of three of Billboard's main country charts (among Hot Country Songs, Country Airplay, Country Digital Song Sales and Country Streaming Songs) marks the first time that an act has tripled up at No. 1 since Florida Georgia Line did so with "H.O.L.Y." On Aug. 6, 2016, the duo's smash led Hot Country Songs, Country Airplay and Country Streaming Songs.

Urban's three-chart rule in the same frame is the first for a solo male since Thomas Rhett's "Die a Happy Man" crowned Hot Country Songs, Country Airplay and Country Digital Song Sales for five consecutive weeks starting Jan. 9, 2016.

As Urban earns his 21st Country Airplay leader, a run that began with "But for the Grace of God" on Feb. 24, 2001, he moves into sole possession of sixth place for the most No. 1s in the history of the chart, which launched Jan. 20, 1990. He passes Brooks & Dunn and Toby Keith, each with 20 No. 1s. Tim McGraw leads all artists with 29 Country Airplay chart-toppers, followed by Kenny Chesney (27), Alan Jackson, George Strait (24 each) and Blake Shelton (22).

"It's a bit surreal, quite frankly," says Urban of his legacy of leaders. "I just wanted to make music and hoped radio would play it so I could have songs in my set that people knew. And, really, that hasn't changed."

"Blue" is the third Country Airplay No. 1 from Ripcord, Urban's eighth studio album, following "Wasted Time" (July 9, 2016) and "Break on Me" (March 12). The album's debut single, "John Cougar, John Deere, John 3:16," peaked at No. 2 (Sept. 26, 2015). After arriving as his fifth No. 1 on Top Country Albums (May 28, 2016) with 93,000 copies sold, the set has sold 412,000 copies to date; on the Jan. 14-dated chart, Ripcord holds at No. 5 (12,000).

In the ever-changing landscape of country, how does Urban keep his music fresh? "We were talking the other day about the pursuit of happiness," he says. "Someone said what it's really about is staying curious. I like that. That's very much where I exist. I'm curious about musical expression in all its forms [and] where mine can go. And I have a real passion for new music, in particular. The possibilities are endless."