For that to happen, I usually do not compose music that is completely notated. The amount of music that I notate is on a sliding scale. At one end of the scale are extended pieces like Donut Music and Buzzards In Love which incorporate improvisation within a highly-notated work. At the opposite end of the scale are minimalist pieces like New Tango No. 1 and Smaller Ups And Downs which have a small amount of notated music and use a particular concept for an improvisational framework. These improv-based pieces are dependent upon the performers to bring the music to life. By having this sliding scale of improvisational freedom ensembles interested in performing my compositions can choose the pieces that are a match for how much freedom they want to have in the music.
I understand how music can have different expressive interpretations given to it by directors and performers. However, I want to go beyond that to embrace a spirit of "Let's see where we can go with this". That is, for performances of my music to be a journey of discovery -- a collective creative process between the composer, performers, director (if one is used), and the audience -- in which the music is alive, spontaneous, and it continues to evolve with each performance. I think of this creative process as being like a jazz solo.
I enjoy being surprised when performers take my music in directions that I had not thought of. There is an element of risk with this approach; however, that is part of the fun and adventure.