Bass drums are large drums which produce a note of low pitch. These drums are used in a variety of different ways, and come in several different sizes. Two common examples include the orchestral bass drum, which is very large, and usually used in orchestras or concert band music, and the smaller “kick” drum, usually a part of drum sets, used in most rock bands. Early bass drums were in fact played by a drummer kicking the drum, but today the kick drum comes equipped with a foot pedal that strikes the back of the bass drum with a padded mallet.
There is also the pitched bass drum, which is mainly used in marching bands and drum corps. The pitched bass drum, as the title suggest, is tuned to a specific pitch. Usually it is played in a set of three to five other drums.
In most popular music, the primary purpose of the bass drum is to keep time. A basic rock and roll beat has the bass drum played on the first and third beats of a bar, with the snare drum on the second and fourth beats. Of course, there are many other possible times and rhythms, especially if you move into a genre like jazz.
Of less musical importance, but still noticeable, the bass drum is usually the most notable element in any drum set simply because it is large and is visible from stage. Because of this, it is frequently the place where the band logo or slogan is placed as well.