In the case of guitar and bass, the musician will usually perform 8 or 16 repetitions of the same note as they follow the harmonic progression of the song. However, a keyboardist will often arpeggiate the 3 notes of the appropriate chord in a harmonic progression. The drummer will play a simple beat, often with syncopated snare drum hits after beats 3 and 4. Emo eighth notes are usually performed at about 115-125 beats per minute (2 eighth notes per beat). example- "Clocks" by Coldplay
Emo eighth notes are usually performed by either a skinny white man with short blond hair and a t-shirt, or a skinny white man with unkempt black hair and a puffy shirt under a black tailcoat.