IMO, a month's notice isn't enough if they're asking you to learn a lot of new material. I'd probably tell them I'll do my best, but suggest that they choose alternatives from a repertoire list for anything I can't get to.

I don't currently have a specific policy regarding timeline. I just handle it case-by-case with the bride/groom. If my wedding season were busier, I might develop a specific policy... something like 60 days advance notice of any special requests?

At the moment, upon initial introduction I send out a list of recommendations, and strongly encourage them to select from that list, since I've already curated music that is both liturgically appropriate, and fitting for the occasion. It helps that I'm almost always playing EF weddings, which reduces the "options" significantly... all of the music during Mass is supplied graciously by Holy Mother Church! That basically just leaves us with discussions of preludes and processions, and perhaps a hymn/motet for Communion, and the occasional request for a polyphonic ordinary.

In the event someone has a special request beyond my recommendations, again, it's just case-by-case. IF it is appropriate AND I feel I have enough time to learn it (or teach it, if it's a choral piece), I'm usually happy to expand my repertoire. If either of those conditions isn't met, then I just politely inform them that it won't be possible to use that piece, and refer them to other options that may be pleasing.

It's a tricky thing, because for the bride, it's her one big day, and she's often expecting to be doted on and accommodated to the last jot and tittle. For us, it's just another Mass to play, and we can't haphazardly shirk our other duties to learn an entire organ symphony by request for a single wedding. I usually find a way to explain that politely if I have a "pushy" client!

Another option I've considered is a sort of tiered pricing, where my basic fee only applies if music is selected from my repertoire. If they make requests for pieces that require serious study, learning, and practice, I would up-charge. But again, my wedding season isn't busy enough to worry about that yet. It's just a thought that's occurred to me in the past, keeping in mind that our musical fees are usually one of the smallest line-items in a wedding budget.

We have a fairly high number of weddings at the USMA Catholic Chapel (two today, and at least one, sometimes two, every weekend from now until late July). When working with that many couples, most of whom are not living in the area, I have found it necessary to set clear directives. A recommended repertoire list with YouTube links is sent at least 3 months in advance (earlier if they contact me sooner), with instructions to return the included worksheet with their choices no later than 6 weeks before the wedding. If I have not received it by then, I contact them with a reminder; as long as they are communicating with me, I don't mind extending the deadline slightly. Our policies state that I will select the music myself if I don't hear from them-- so far, that hasn't actually happened. The document also states that the music director's decision regarding the inclusion of any selections not included on the recommended repertoire list is final, and I'm very fortunate that our chaplains are willing to support me in this.