Glebe has three main bands: junior, senior, and jazz. Junior band is generally for grade nine students, while senior band is for grades eleven and twelve (although it is possible to get in before then, more on that later). Grade tens are supposedly in another band, called the intermediate band, although all this means is that they can choose to go to either the junior band or senior band practices. Grade tens who choose to go into senior band also have to play with the junior band during performances.
Most grade ten students do choose to go into senior band, and some grade nines get in as well (generally by invitation). Junior band practices start at 7:30 in the morning on Mondays, Wednesdays, and occasionally Fridays; senior band only practices on Mondays after school, but its practices are much longer (generally end around 5:15 to 5:30).
If you're in grade nine (or any other grade, for that matter) and fairly confident in your playing, jazz band is a fun way to get some more practice, and yet another additional music credit. Note that jazz band doesn't have the same instrumentation as the other bands (i.e. no flutes, euphonium, tuba, clarinet, oboe, bassoon, french horn, etc.), but it is worth learning to play another instrument for, so grab yourself a trumpet and get to it. Jazz band practices at lunch on Mondays and Wednesdays.
All bands practice in the music room (room 14, in the basement), and the most up-to-date information about them can be found on the blackboard and electric-scrolling-thing at the top of the stairs. Of course, this site should contain reasonably new stuff about it as well, but if you forget something I have absolutely nothing to do with it. Good? Good.