Who should write references for me in a mid-career job search? I am a tenured professor planning about seven years past the Ph.D. Over the past few years, I've applied to a handful of jobs (I haven't been looking aggressively -- just applied to the good opportunities that came up, along with 500 other people).

My references usually come from:
1) My Ph.D. advisor (who has moved to a new institution since I finished my Ph.D.).
2) another professor who taught me in graduate school.
3) a mid-career professor from another institution who has read some of my publications.  He's not a super-star academic that anyone from any field inmy discipline will know, but he is established and well known within my particular field.
4) (for jobs requiring four reference letters) another professor from my graduate institution.

This is basically the same set of letters I have used since I was on the market as an ABD student seven years ago.  They worked back then for finding a tenure-track job, but I'm wondering now if I should shake things up -- perhaps get away from having any letters from people at my graduate institution other than my Ph.D. advisor, for example.  I worry that the letters from professors who only knew me in graduate school will seem stale (and frankly, I haven't had much contact with these people since I graduated, so they probably can't comment in detail on what I have been up to since I was a student).

If I don't continue to rely largely on letters from professor at my graduate institution, whose letters should I replace them with?  People who I think were anonymous reviewers for my books and articles?  People who I think wrote letters for my tenure review?  People in my current department whom I trust (this is tricky, of course, since I don't want to advertise too loudly within the department that I am applying for new jobs)?

I'm in the humanities, for what that's worth.
At 7 years post PhD, your letters are getting stale, in that your PhD advisor, probably is no longer the person most familiar with your work. The person who taught you in grad school is definitely not going to be the most familiar with your work. It sounds like you did not provide a list of names when you went up for T&amp;P. If you did, you should reconsider those names.

Some possible ideas of letter writers:


Find someone who is teaching from your book(s)
The person you most like having a beverage with when at a conference
The person who has, or that you would ask, to write a blurb for your book jacket
Someone who has invited you to give a research seminar or be on their conference panel
A trusted colleague in your department or at your university