The mark is a sound. The mark consists of a 5-note melody performed in unison, 1 octave apart, by a whistle and treated acoustic guitar. The final two notes of the 5-note melody are accented by treated hand claps. The final note of the melody is also accented by a quiet, non-pitch-specific bell. The whistle performs the following notes: An A4 eighth note, followed by a G4 eighth note, followed by an A4 eighth note, followed by a C5 eighth note, followed by an A4 quarter note. At the same time, the treated acoustic guitar performs the following notes: An A3 eighth note, followed by a G3 eighth note, followed by an A3 eighth note, followed by a C4 eighth note, followed by an A3 quarter note. The melody begins on beat 2 of the bar and ends on beat 4. The first three notes of the melody are slurred with a more legato articulation. The final two notes are performed more staccato, with separation. The final note involves a slight fall/bend in pitch in the whistle performance. The key is C Major. An electric guitar swells gently underneath the 5-note Sonic Logo melody with an A minor chord. BPM is 114.