You can write your  own music.  Take a melody you like and match it up with some words from the haggadah.  You can adjust the words to match the music.  Use melodies that everyone knows and that you like.

I have used a number of melodies to sing parts of the seder.  My daughters asked me to use the Brady Bunch song in the haggadah when they were very young.  Below is the result:

The following Hallel hymn uses the music from the Ballad of Davy Crockett:

We use Do Re Mi for one of the Hallel  songs:

I used the melody from the song “I Believe” from the Broadway play Book of Mormon for the portion of the seder where we welcome Elijah: