Great album, and the beginning of a whole new era of Waits' music. His wife Kathleen Brennan had been introducing him to a range of avant music and began collaborating on songwriting with him and it really starts to show with this album.
To me, this album feels like Waits' drunken barfly character fell so far down his hole of inebriation that he ended up in some strange hallucinatory underworld. The opening track "Underground" could be seen as a signal of this, or a paean to Waits' own new musical discoveries courtesy of Brennan "It's a place I've found/There's a world going on/Underground. The album title seems like something of a nod to Captain Beefheart's "Trout Mask Replica" too.
The other image the music conjures up for me is the Waits barfly joining a travelling circus and hitting the road. The jarring instrumentation holds a definite carnival vibe, and Waits practises his ringmaster's holler on several tracks. There are still one or two gentle moments here, including the melodic outro of "Rainbirds", providing a nice contrast to the abrasive opener.
