Accent on Achievement-Bb Clarinet instruct Book 3, by John O'Reilly & Mark Williams. 

Book 3 will help you to develop the musical and technical skills necessary for a lifetime of great music making with your B flat Clarinet.

The "Keys" to success:  Progressive Technical and rhythmic studies in all 12 major and 12 minor keys.

You will learn new rhythms and meters, and also improve your tone and intonation while playing a rich variety of chorales. 

With diligent practice, there's no end to what you can accomplish!