This music chart debate has been going round and round here for far too long. There's a BIG difference between having your nose buried in a book when performing vs simply using a chart as a road map. Though I've got my core repertoire memorized, I always keep a lyric and/or chord chart discreetly handy to cue me in for 'audience requested' songs that may not be so fresh in my memory. Only when featured as the lead/solo performer in a 'stage show' setting and playing a specific song set, will I make sure I have all my material fully memorized.