There is really memorizing the songs...and make believe you remember

If you can turn off the arranger and comp with melody in original keys...then you really remember the song....If you 2-5 your way through a tune with the arranger on..you are make believe

Performers with strong vocals, can get away with lazy play...filling in spots and basic chords....Not mentioning names ..but I have a couple friends in this category

I can remember most of the tunes I learned in original keys, and as Ian...I use substitute chords when I can.....but lyrics is another bag...I need them..I am getting better...maybe if I sang for all the years I played..I would be okay, but I liked the way I did it...surround my self with talented girl singers