Thanks! Yes, I like a lot of Paul Simon songs. I'm not experienced in singing, apart from having sung in a small choir a long time ago. It's only a side line for me.
Not sure what you mean about the bass line though. I recorded all instrument tracks playing them manually. I played the fretless bass as close as possible to the original version I heard on Youtube. There are one or two points where the guitars have a retardation coming late for the right chord, maybe also the bass at that point, maybe that's what you're referring to. But an automatic bass couldn't do this pattern, as it foresees the next harmonies and leads towards them.