The Doobie Brothers appeared to be stalling out. A year after their multi-million-selling Captain and Me album spawned a pair of Top 20 hits in "Long Train Runnin'" and "China Grove," the band's follow-up studio project was going nowhere.

After all, What Were Once Vices Are Now Habits was created in the usual way, with the Doobie Brothers gathered in the studio to expand on unfinished individual ideas. "We basically wrote whatever came to mind," co-founder Tom Johnston told the Courier Post in 2014, "and brought it to our rehearsals to work up."

These jams, overseen once again by producer Ted Templeman, found the band stitching familiar elements of rock, soul, folk and blues together with honeyed vocals, boisterous dual drumming and riffy guitars.

Moments like "Another Park Another Sunday," the album's first single, came together effortlessly. "Songs like that write themselves," Johnston told Veer in 2013. "From 'Listen to the Music' to 'Another Park Another Sunday' or most recently 'World Gone Crazy,' those kind of songs, when they happen it's like somebody else comes in and sits down with you that you can't see. It's your stuff, it's coming out through you, but you're acting as a transfer mechanism."

Templeman had a knack for making small, but musically important adjustments. He suggested they run the guitars through Leslie speakers, for instance, and "Another Park Another Sunday" was complete. He also brought in the Memphis Horns for these sessions, giving What Were Once Vices Are Now Habits a muscular soulfulness.

Johnston's distinctive rhythmic approach powered the album's second single, "Eyes of Silver." This sound traced back to his initial demoing process. "That style — on 'Long Train Runnin,'' 'Listen to the Music,' 'Eyes of Silver' — what I call that chunka-chunka rhythm, was something that got developed because I didn't have a drummer handy," Johnston told Veer. "That way you can play drums and guitar at the same time. I developed it on acoustic rather than electric, and then I just transferred it over."

Listen to the Doobie Brothers' 'Another Park Another Sunday'

What Were Once Vices Are Now Habits – which arrived on Feb. 1, 1974 – expanded to include four songs from fellow co-founder Pat Simmons, bassist Tiran Porter's spacey "Flying Cloud" and the band-written "Road Angel." (That marked the final songwriting credit for Michael Hossack; he was replaced during these sessions by new second drummer Keith Knudsen, and didn't return until the late '80s.) Still, the bulk of the creative work fell to Johnston, who wrote or co-wrote seven of the album's 12 tracks.

The expectation was that they'd continue a string of Johnson-sung successes that stretched back to the group's breakout 1972 song "Listen to the Music." And maybe that was the problem: The Doobie Brothers needed to go further than another patented Templeman tweak in shaking things up.

"Another Park Another Sunday" got to only No. 32, then "Eyes of Silver" stalled at a paltry No. 52. What Were Once Vices Are Now Habits was shaping up as a major commercial disappointment. On top of that, Johnston's 1973 arrest on marijuana-possession charges in Visalia, Calif., led to court hearings just as the album was the arrive.

Then a disc jockey flipped over one of the Doobie Brothers' singles and found "Black Water."

This Simmons-led number initially emerged from an earlier jam during the sessions for The Captain and Me. "I was sitting out in the studio waiting between takes and I played that part," he told Guitar Player in 2011. "All the sudden I heard the talk-back go on and Ted Templeman says, 'What is that?' I said, 'It's just a little riff that I came up with that I've been tweaking with.' He goes, 'I love that. You really should write a song using that riff.'"

Templeman oversaw a rootsy turn on viola from Novi Novog, while Simmons populated the song with a series of resonant images from a period when the band would set up a base camp in Louisiana during tours of the Deep South. It broke the Doobie Brothers hitmaking mold, then created a new one.

"I was fooling around with this open-tuning thing in the studio and I started writing some lyrics about New Orleans," Simmons told the Sun Herald in 2018. "I was spending a lot of time there. The lyrics 'If it rains I don't care, don't make no difference to me, just take that street car that's going Uptown' is a true story — as is 'I want to hear some funky Dixieland,' because there was a lot of Dixieland bands playing in the French Quarter."

Listen to the Doobie Brothers' 'Black Water'

Johnston and Simmons were West Coast guys, but both had been drawn deeply into the sounds of the Mississippi Delta. It surrounded them in Louisiana, and "Black Water" emerged.

"We'd never even been to New Orleans until 1971," Johnston told Veer. "We were supposed to do a date with Jackson Browne, Chuck Berry and the Eagles, and it got rained out. That was the first time I'd ever been to that town and I just fell in love with it. Then we started going down there fairly frequently and we were just mesmerized by everything. There is so much culture there – from the graveyard to the French Quarter to the old Confederate places. The food is unbelievable. And the music. I was way off into New Orleans music before we went down there, and I didn't even know it."

The Doobie Brothers' first No. 1 song almost went unreleased, however, because Templeman never pictured "Black Water" as a single. But fans fell in love with Simmons' paean to New Orleans, starting in the Roanoke, Va., area where a tributary called the Blackwater flows.

"Black Water" was re-released as an A-side in November 1974, this time with Johnston's album-opening "Song to See You Through" as its backing track. A now-revived What Were Once Vices Are Now Habits went double platinum, soaring to a then-best-ever No. 4 spot on the Billboard chart in March 1975 on the strength of this out-of-nowhere smash single. The a cappella section quickly became a singalong staple.

"I remember when I first heard it was No. 1, we were in Baton Rouge, La., and we were just getting ready to go onstage," Johnston told Songfacts in 2009. "I guess [band manager] Bruce [Cohn] must have told us. I remember I went in and congratulated Pat backstage. And we've been playing it ever since."

Doobie Brothers Albums Ranked

They remain an intriguing dichotomy of a band.