The Doors guitarist Robby Krieger recalled the band's struggles with their third album, Waiting for the Sun, which will be expanded and re-released on Sept. 14.

His comments coincided with the release of a previously unheard rough mix of “Spanish Caravan,” which appears in the new set.

“We had enough songs for two albums before we ever went in to record the first album, but by the time the third album rolled around you're kind of out of songs," he told Billboard. “So I ended up writing more of the songs for the third album. I got to do stuff like 'Spanish Caravan' and 'Yes, The River Knows,' stuff like that. We created some stuff right there in the studio, like 'Five to One.’”

You can listen to the rough mix of "Spanish Caravan" below.

Singer Jim Morrison was beginning to drink heavily at the time, Krieger recalled, though he understood why. "By the time of the third album, we had enough money really spend a lot of time in the studio recording," he noted. "So Jim would get really bored 'cause you'd spend six hours on snare drum sound and the vocal is always the last thing to be recorded. … He would end up going to the bar and getting wasted and was useless after that.”

Another issue was the increased number of hangers-on, also due to the band’s success. “[Producer] Paul Rothchild had to yell and scream a couple times and throw people out of the studio,” Krieger said. “It was kind of crazy."

The guitarist also confirmed that plans were being made to release a 50th anniversary edition of The Soft Parade, which originally arrived in 1969.