In selecting a solo, a rule of thumb is: Be able to sight read fairly well through the part in order to be able to perform it well at the concert of recital. Many players choose music that is much too difficult for them. Choose something challenging, yet something that is playable and enjoyable. Concentrate as much on the musical and stylistic elements as you do the technical. Above all ask for assistance when you have a problem. Play your solo for any who will listen.