I think the problem comes from 'trying' to sound like the record, and failing...

For me, it's more important to work with the SONG, and not worry too much about the arrangement. As long as the 'spin' you put on the song is still fresh, groovy, and entertaining, I think that the audiences still seem to appreciate it. But when you coldly go through the motions, and although get technically 'close' to the original, miss it's drive and passion (what made the audience like the song in the first place), you are always going to get that 'cold shoulder'.

And, let's face it, you old geezers, no amount of sounding like the record is going to make a kid jump around to your latest Kanye West cover. SOME musics are just NOT meant to be played by the elderly!

If you find yourself covering a lot of tunes by artists you wouldn't normally listen to, or enjoy, it MIGHT be time to consider a different venue, where you can play what YOU enjoy, and then, no matter HOW far away from the original version you stray, you are still playing stuff you love, and the audience ALWAYS gets off on that!