Originally posted by Christoph

Righteous.

The fingering I had for Fm13 was - (x 8 10 8 9 10) Basically a minor 7th with a 6th. The problem is that the 6th (D) is outside the diatonic structure of the key I'm playing in. The proper note for the key would be a Db. Which would make that chord an Fmb13, right?

Right now I'm thinking that whoever wrote this chord chart didn't know what they were doing.

Correct. To make this a lot easier on your self play a Bbmin9th instead. Sub out the root for the 9th like this (xx6668). If you wanted to you could even put F in the bass quite comfortably ((x86668).

NTM....Minor, Major, and Dominate7#11 chords are actually quite common, I would even go as far as saying more common then chords that contain the natural 11th. The natural 11th does not sound good within a chord, to "sus" sounding.