But for best results, you'll need to "condition" the AC signal and convert it to varying DC with a peak detector.No Way, dvddoug.
How about ac-coupling the signal and clamping it (if that's necessary)?
But...
The LM3915 is for a log display.
The LM3916 is for a VU display.
(The LM3914 is for a linear display.)
Adding link