I used Gelatos for the yellow and blue background, over tissue paper (with the music pattern on it) as well as some stencilling. The border is hand drawn with a Micron pen and filled in with Faber Castell PITT pens. The heart was done by hand and coloured with Gelatos. I've even got some beads and glitter pen on there. Fun stuff! You should really try it, if you get the chance.
Have a great weekend. :D