GRADED THEORY:

If you are currently studying music at a college or school, you will  know that The Associated Board (ABRSM) Grade 5 (Theory) has a special importance for all music students, who must achieve this standard before they can progress to the higher Grades in the ABRSM instrumental exams.  This, alone, makes theoretical study an absolute must. If such is your aim I will ensure that you succeed in all grades leading to, and including, grade 5 itself. Then, should you wish, I will take you through to "degree" level.

PRACTICAL THEORY:

Some music students are uncomfortable with the term  theory, because they have an impression of a set of mechanical rules and regulations that must be adhered to.  It is even thought - in some quarters - that  knowledge of  theory actually restricts the creative flow!
Nothing could be further from the truth. Music theory is not a restrictive influence; it is the foundation that gives musical imagination the widest possible scope for emotional expression.
The more theory you internalise, the more inventive your playing becomes. In other words; the more you know, the better you play.

You can certainly ignore music theory if you wish, and your innate musical sense will still allow you to create something that works.  But if you take time to understand the structures, your options will expand accordingly and you will move on to richer, more original, more satisfying creations. 

Ideally, theory should be studied separately from an instrument. The reasons for this are many and varied. Normally, however, as I teach an instrument, I will include whatever theory is necessary to that hands-on skill. 

In improvisation, knowledge of key signatures/chords should be fundamental. Below is a short exercise you might like to complete.
     If you are at the stage where further study of theory is not needed, the answers will instantaneously spring to mind.