I've made several Hannah Montana Guitar Cakes. I start off with making a template of the guitar shape, appropriate to the size of cake I need (how many people it will feed). I downloaded a picture of a Hannah Montana guitar, and traced it to scale on paper and then used that as a guide to cut the shape out of rectangular cake.
The frosting is tinted buttercream. I took the logo and cut each individual letter and placed it on the cake where I wanted them and used a toothpick to trace the outer edges of the letters. I use this practice often in all my cakes. Then, I use the frosting to outline those shapes and then fill them in.
The cord tightener (or whatever you call them), are lollipop sticks with mini-marshmallows on the end. The rest is all frosting. You can't see, but I write "happy birthday" and the person's name on the sides of the cake. The neck of the guitar is made from a rectangular cake. I just cut it to scale and piece it together. Those pieces I use frosting as glue to help hold the pieces together.
In this case, the neck and the very end are two different pieces so 3 pieces altogether made this cake. To get the mutli-colored look, I alternated the colors as I placed them in the frosting bag.
I made this Hannah Montana Guitar Birthday Cake for my niece on her 8th birthday, as she was a huge Hannah Montana fan. I made 4 cakes using a large cookie sheet pan and cutting out the shape of the guitar and using the extra pieces of the cake to assemble the Guitar handle. This cake is a 2 layer cake that was frosted in the middle with whipped white frosting and stacked.
I used neon food coloring to get the lavender color of the guitar, then used black glitter frosting in a tube to outline the cake. I also put on "strings" on the guitar using the black glitter frosting in a tube. Then I outlined the guitar cake in a pink frosting that I piped with an ordinary piping tip. It was easier to outline the white portion of the guitar and frost the lavender first.
The cake was just whipped frosting and smoothed with a butter knife and I used miscellaneous cake sprinkles to decorate the top of cake. Very simple, enjoy.
My niece was told after three years of High School Musical NO MORE! So she wanted a Jonas Brothers cake. I decided to make it into a guitar. I cut a electric guitar shape out of paper and used that as a template.
After baking and preparing two 11x15 cakes I cut out around the template and frosted. Once frosted I used a picture from the internet to guide my design of the fondant. I fell in love with the little star cut-outs so I cut out stars out of the pink then did the same with the teal and interchanged them. I used dental floss for the strings.
I had found pictures of the JB on the internet and a copy of their autographs, I asked a local bakery make a Jonas Brothers wafer complete with autographs. I then traced the autographs to make them look real.
This is the how the Jonas Brothers Guitar Cake turned out. I think its my best cake yet!
This Stratocastor Guitar Cake is to scale and all edible with the exception of the board. The cake is covered in rolled fondant and embellished with hand made "Hardware" which is painted with edible silver leaf.