...
MUSIC models the influence of infiltration through the sides of the system. This is important, since a number of studies have shown that this can represent a very high proportion of the total infiltration of the system. MUSIC has been calibrated for a number of infiltration systems, both in the field and using detailed laboratory studies, to derive a default Horizontal Flow Coefficient of 3.0 (ie. the lateral infiltration rate being effectively three times the rate of vertical infiltration through the base). You should only modify this value where they have appropriate data to calibrate it; these data should preferably be based on published, peer reviewed studies.
Note: Advanced Properties are uneditable by default. You can make it editable for each project by clicking on Edit and Project Options. This will present you with a Project Options Screen as displayed below:
Now, click on MUSICX Treatment Node Settings and tick on Editable as shown above.