If you can afford or are able to do so, I would suggest opening with Whitney Houston's rendition of the song from the film, "The Bodyguard." Before she became fodder and inspriation for the tabloids, Houston could really deliver a song and she belted this one out in a dominant manner. I think that it would be an effective way to grab the audience's attention at the start of your presentation to show either the video of the song or clips from the film with the song in the background might be a good way to "hook" the audience into your presentation. The only advice I could offer is that Houston's rendition can open your presentation, but the bulk of what you are going to analyze is probably going to be Parton's original song. It is important to use Houston as an opening, but she is not the original author of the song and Parton should receive the lion's share of the attention in your presentation in recognition of her work.