Modern computer software enables you to change your own compositions so that they sound as if other composers had composed them. The programs make use of neural net technology to learn the composing style of any composer. Neural net composing software is available on the internet.
You enter the melody (over the computer keyboard or by loading midi files) and choose a composer and the program does the rest.
You can train the programs neural nets to compose like your favorite composers. All you need are ten to twenty works of that composer as midi-file. The neural nets then analyse the composing style and make it available to you. By choosing just one song for analysation its possible to let the program compose in the style of that song.
Have your songs composed to the style of Andrew Lloyd Webber, Bethoven,...any composer you can think of..or in the combined style of your favorite musical: Cats, Phantom of the Opera, etc. Everything is possible if you have enough midi files to train the neural nets.