1 there is no point having canonical on a 404 page. I would say its a very confusing signal to bots

2 don't always 301. 404 exists for a reason. In most cases I will 301 old pages but there are cases where letting pages 404 is the correct way forward

Ryan are you using the client's email address? Seems it may get a better response rate

You have exactly the same content as a million other lyrics websites, so why should Google be interested in your PR0, PA18, DA2 website?

I think your doing pretty good with 15000 pages indexed via site:http://lyricstatus.com

I think what you need is a USP, not technical seo responses

canonicalise your urls

more content on the homepage

Get rid of crappy stock photography, makes you look spammy. Have large, quality images

Id add an image with keyword relevant alt attribs

Add a google map with your location

Also have a Google for optimising pdfs for search, i know there are number of ways & options

http://www.seomoz.org/ugc/how-to-optimize-pdf-documents-for-search

http://searchengineland.com/eleven-tips-for-optimizing-pdfs-for-search-engines-12156