I had a request for lyrics to be written. I talked it through with the buyer, and they said that I should write according to the feeling I get from the song.
I submitted the lyrics as well as a topline for the music, only to receive a modification request to change the topline in a way that doesn’t go with the lyrics I have written.
I am now expected to redo the entire song. Surely this is taking advantage.
What can I do?
A buyer does have rights to ask for modifications. A good approach is to send partial work (20-30%) as a first draft and ask the buyer to give feedback on it. Then based upon his/her feedback, you can complete the rest of 70-80% work. This will minimise the chances of doing all the work again from zero.
They only have the right to modifications if the seller offers them. Buyers do not have the right to ask, demand, or insist upon work that the seller does not offer, or that the buyer is not willing to pay for.
No, no, and NO! This is TERRIBLE advice that could get you warned or banned from Fiverr. Fiverr requires that all deliveries be the complete delivery of all of the work the buyer asked for. You cannot, and should not deliver partial orders.
Please do not give false advice.
I didn’t ask him to deliver partial work. The partial work needs to be sent via inbox for the sake of review.
Writing an entirely new song is not a modification.
You may not consider it a modification but Fiverr and the buyer will call it modification.
It’s not about what the word means to me. The definition is to change something slightly.
I got this and my buyer get mad at me because I don’t want to deliver partial orders with no watermark on it. 
As a lyric writer myself, when it comes to modifications i only offer a maximum of 2 bars. If i am working with a new client i might write 4 bars (out of 16) as a preview. If they like what they hear i will send them a custom order. Once accepted i continue on with the project until completed.
Absolutely not. Deliver pre-delivery samples to look at as attachments within the order itself. Then, when everything is settled via discussions (within the order!), deliver your work. Deliveries complete an order, and the buyer is then able to mark the order as complete, and post a review of the final delivery, or process a revision request.
Under no circumstances should you be doing any of the what you have advised.
Why does it matter where you send the samples?
I matters because Fiverr requires all deliveries to be the FINAL product.