job search - Who to address on the cover letter?

In the cover letter of an application to an academic job, should we write

Dear Search Committee Members,

or

Dear Professor A, Chair of the Search Committee Members,

or

Dear Professor A, Chair of the department

or what else?

In case we don't know who the chair of the Search Committee is, should we write the department to ask?

Answer

I address all cover letters, letters of rec, etc. "Dear Committee Members:" Don't waste your time addressing it to an individual. The only thing you can achieve by doing that is embarrassing yourself and giving the search committee the chance to have a good laugh at your expense. If you do it correctly, it doesn't actually achieve anything; why give yourself one more thing to stress about?