Twins of El Dorado have one of the most unique sounds you will ever hear. Joe Moffett plays the trumpet during these songs while Kristin Slipp sings. To think of this in a smooth jazz way would be one thing, but the way that these songs go is actually quite different. The structure is all over the place and so are the vocals, which makes it perfect for me.
A sound like galloping can be heard at first and then slowly the singing comes in with the trumpet following along. It's interesting because at first it can be a matter of singing a note and then the trumpet playing a note after it, but as the cassette goes on the two sounds can merge together, playing at the same time and becoming one.
There are moments when the trumpet is solo, the vocals take a break, and though there are clear lyrics in here at times there are also words that are mumbled/jumbled as well as just this breathing rhythm which produces vocal sounds but not words. There is a song called "Cats" and it's about cats not wearing shoes, which I think is fun in an IASIP way.
In true contrast to this sound overall, sometimes it can sound like a slurping with the vocals and other times as the singing comes through it reminds me of someone classically trained such as Julie Andrews. On "Dorsal", for example, the vocals go "ho" and then the trumpet plays a note. Though you've likely heard singing and a trumpet before, I'm willing to be you've never heard them together quite like this.