"When you are writing arrangements of the tango and other Latin American music for classical string orchestras, there are some special challenges. Most of these involve how one can incorporate all the musical elements that are not included as part of the notation. Things that the musicians just know because they know the style, but that are not written down, and are often very difficult to notate. In the tango one often talks about playing 'con mugre' (with 'dirt under your nails'), which is a way of describing all the small nuances in the playing that must be there if it is going to feel right, but that are not necessarily 'correct' on the instrument. This often involves untraditional ways of creating added sounds and effects while you are playing, or the way you use accents, staccato, glissando and crescendo, at a subtle and detailed level that is often difficult to distinguish from a particular musician's personal style. How much of this can be marked in the music notation? I am constantly experimenting to find a good balance that does not include so much information that it becomes impossible to read/play, but enough to give it a reasonably authentic character." (Sverre Indris Joner, Arranger, pianist and composer)