Written by Humble Pie lead singer Steve Marriott, 30 Days In The Hole is about getting busted for drugs and getting sent to jail. Marriott got the idea after playing a show in Kentucky, where he learned that getting caught with drugs earned you 30 days in jail. He was also thinking about a friend of the band's who had been sent to jail for having a joint.
Marriott was making the point that drugs were a part of culture (just as alcohol was a generation earlier) and there was nothing wrong with it. In many ways, the song is a call for legalization.
Marriott has said that inspiration for the title came from a Humphrey Bogart/James Cagney movie he saw on TV, where Bogart plays a prisoner who gets sent to "30 days in the hole."
Marriott may have been referring to the 1938 movie Angels With Dirty Faces, although that line is never uttered in the film. It's also possible that the film was Somebody Up There Likes Me, a 1956 movie where Paul Newman is threatened with the "30 days in the hole."
This wasn't released as a single in the group's native UK. It was only released in the US a year after the album came out. Dave Clempson, formerly of Colosseum, had recently joined the band as guitarist. This was one of the first Humble Pie songs he contributed to.
There are several drug and alcohol references in this song: "Red Lebanese" and "Black Napalese" are forms of hash, and Newcastle Brown is a kind of ale.
Mr. Big and Gov't Mule are among the acts to cover this song. Ace Frehley and Robin Zander (Cheap Trick lead singer) covered it for Frehley's album Origins Vol. 2. Said Frehley: "I'm a big Humble Pie fan, but there's no way I could reproduce a Steve Marriott vocal. He's just too good of a vocalist – may he rest in peace. I thought of Robin Zander because we used to tour together in the '70s. Cheap Trick used to open for Kiss, and we became good friends during that period." From: https://www.songfacts.com/facts/humble-pie/30-days-in-the-hole
