Where to sit (or stand) at a performance
When attending a concert of gagaku in a concert hall, it is probably best to decide where to sit according to what you are interested in. Seats toward the front of hall afford a good view of the details of the costumes and delicate movements of the dancers in a bugaku dance program, and of the performance techniques of the instruments in kangen instrumental music. Seats further away from the stage offer a full view of the stage, and facilitate a grasp of the performance as a whole. If balcony seats are available, this vantage point can make it easier to grasp the geometrical, often symmetrical, patterns that are formed in dances with more than one dancer.
Less consideration is required when attending performances of gagaku at temple and shrine festivals, which are generally free of charge. At these events, gagaku can be enjoyed along with the nature or traditional architecture of the setting. These events often show regional differences, which can be interesting to compare. The stages used for gagaku performances generally have nothing blocking the view, so outdoor performances can generally be watched from any angle.
Things to be watched for on first acquaintance
Attending a gagaku performance for the first time can be somewhat bewildering. Perhaps the first thing to do is to grasp the difference in the timbres of the instruments. This is easy to do in the first piece of a kangen performance, namely the short prelude netori that introduces the mode of the longer pieces that follow, since the instruments enter one-by-one in a specific order: mouth-organ shō, reedpipe hichiriki, transverse flute ryūteki,, barrel drum kakko, lute biwa, and zither sō.
In bugaku dance performances, what is most important is the distinction between Dances of the Left and Dances of the Right. In all but a small number of exceptional cases, Dances of the Left are accompanied by tōgaku (‘Tang music’), with the distinctive timbre of the mouthorgan shō, while Dances of the Right are accompanied by komagaku (‘Korean music’), which lacks this instrument. Dancers of the two directions enter the stage from different directions: viewed from the front of the stage, those of the Left enter from the left of the stage, while those of the Right enter from the right of the stage. The most conspicuous visual difference is that of the colors of the costumes, with Dances of the Left generally using red or other warm colors, and Dances of the Right using blue, green, or other cool colors.
Usually information is available about what pieces are to be performed at any given performance. A quick perusal of available resources beforehand should make any opportunity to see gagaku in performance that much more worthwhile.