I felt the same having gone around the room with my set list looking for someone to play melody with me. I got lots of favourable comments on my set list but it when I'd pick up on comments such as "I like that one" or "That'd go down well here" I was told "it's too difficult on guitar" and "it's not a standard".
Despite having over thirty well known tunes in my set I couldn't hook up with anyone who'd do the homework and make it happen on the following jam.
Bah!
With @PaulWarninglast year, we'd discussed doing an Open Mic with some tunes that he and Wendy had been doing the rounds with as a punk duo. He let me have clips of them playing some tunes and I hacked out the bass lines for them at home. We met up after about a week and did those tunes and one other that we knew each knew independently of each other at the Horse and Groom. Simples. It ought to work for Jam nights too
That was, as I realise now, an exception to the rule.