In case you are going to put your digital art in YouTube, you need to know the right steps of this process. Fist and most important is to create a slideshow. Click File, New and then Slideshow.
Name your slideshow and click Choose Theme, then simply drag the images and rearrange them the way you want. Next step is to add the music. In case you can’t find the right track at your PC, take a look at the Legal Music for Videos page on the Creative Commons official site.
There you can choose between thousands of tracks. Import the music into Aperture as you drag the audio track into the slideshow.
After that you will see under the Library button some options for music with a little music icon. Drag the song from the icon down to your images and it will start to play anytime you are opening your slideshow. The next step is to export and upload your file to YouTube. Click the Export button and you will see an open dialog box where you will name the file, choose a format and where to be saved.
Pick the option Mobile Me, YouTube and then click Export. Being converted your image will be ready for YouTube.