I don't know whether this helps AlexBell, or is exactly what you mean (?), but the code that I use on my website for formatting poetry with indented lines (and hanging indents) is this:
Code:
.poem {
margin: 1em 0 0 1em;
}
.poem p {margin: 0 0 0 2em; text-indent: -2em; padding: 0;}
.poem p.stanza {margin-top: 1em !important;}
.poem p.indent1 {margin-left: 3em !important;}
.poem p.indent2 {margin-left: 3.5em !important;}
.poem p.indent3 {margin-left: 4em !important;}
This allows you to have progressively indented lines and creates hanging indents when the lines wrap.
I can't remember where I got this code, probably some kind soul on this forum, and my background certainly isn't in this field, but it works for me. If there is an intrinsic problem with it I'm sure that someone who actually knows what he/she is talking about will put you right.