We've got an existing question listing fonts similar to Avant Garde: What's a good replacement font for ITC Avant Garde Std?. It might be one of the very similar fonts listed there (e.g. Tex Gyre Adventor or Raleway).
But to answer the other implied part of the question - is it likely that they modified the type for this album cover? - yes, it's very common for type to be manually modified and in some cases redrawn for anything that is like a logotype.
If the goal is that a piece of type is itself to be a recognisable design, or, is to form a significant part of a design that is to be recognisable and distinctive, it's very common for a designer to tweak the typeface, going over every corner, every line and every flourish and serif, where appropriate redrawing them to be just right for this usage.
For something like cover artwork for a major artist, it would be surprising if the designer didn't tweak and perfect for their eye this specific set of letters, even when working from a classic typeface like Avant Garde.
For one thing, that
' is definitely not from ITC Avant Garde Bold:
Looking at it, it looks like many of the letters might be a lighter Avant Garde (demi-bold?) with a stroke applied, which would explain the
R and the seemingly smaller counter (hole) in the
O as well as the more even thickness; alongside tight tracking, manual kerning and swapping the
' in from another font.
A modified, stroke-fattened Avant Garde demi-bold using a single close quote (
’) and the low-slung
A from the 'Bold' font looks likely: