Getting references after a company closes after 15 years as an event coordinator

I worry a reference will only confirm dates of employment. Any experience at all would help. I have one former client who liked my work. How do you ask politely?

Thanks for writing this out. I went through something close to it last year, and it settled down once I kept a simple log of every call and form.

I kept a note of my results so my references could be specific. They appreciated it.