I think that the most obvious similarity is that they both love music. Mozart and Salieri were able to appreciate and love music at a leve that was uniquely different from others and from their contemporaries. While Salieri lacked the artistic capacity of Mozart, it did not prevent him from being able to fully love the beauty and aesthetic of music like Mozart. Both of them understood how music composition would be key to their own longevity and their own reason for being in the world. Neither one of them was able to develop any other reason for consciousness other than the love of music. With both of them, music was not a job or a profession, but rather it was a way of life. It was something that allowed them to transcend their own being and enter into a realm that few, if any, could grasp. I think that both of them are similar in this regard, in that both of them loved music. Mozart was on an entirely different and more elevated plane of being with what to do with his talent, but the same love and passion for musical creation was evident.