percussion soli (drum roll-off) as heard in "Semper Fidelis" by Sousa. Another example of a trio introduction is found in "Twin Eagle Strut" by Zane Van Auken. The third (or technically fourth or fifth) primary melody in a march is called the trio, which usually is the main melody of the march. It typically is played legato style in a softer dynamic and features woodwinds more than brass. Sousa often used clarinets and euphoniums in lower tenor register in his trios. This trio strain is the most contrasting of the sections, often containing variations of motifs heard in the previous two strains. The trio melody may be repeated once at a softer dynamic, or may not be repeated at all. Typically, it is played quietly for the first or second playthrough, then features piccolos (or flutes, or other woodwinds) playing over the trio melody. In almost all cases the trio now modulates to the subdominant key of the march, meaning one flat is added to the key signature. The key is now flatter and this repeat will, with softer instrumentation, offer a relaxing feel from the previous volume. The contrast makes the trio more memorable as the new key is maintained to the end of the strain. (For marches starting in minor keys, the trio usually modulates to the relative major.) Next comes the breakstrain or breakup strain (sometimes called the dogfight or interlude), making it the fourth melody heard. This strain is loud, intense, and marcato. Its purpose can be found in its title, as it literally breaks a gap between the trio sections, providing contrast to the usually softer trio melodies and generating excitement for the listener. Most breakstrains resemble a conversation between the upper woodwinds and the low brass. The final measures typically contain tension-building chords or chromatic motifs. The breakstrain is usually 16 bars long, as in the case of "Hands Across the Sea", but marches vary: "The Washington Post" and "The Interlochen Bowl" have eight-bar breakstrains, where "On the Mall" and "The Purple Pageant" have 12-bar, and "The Thunderer" has a 15-bar breakstrain. "The Stars and Stripes Forever" has a 24-bar breakstrain. After the breakstrain, the trio is repeated again. The trio after the breakstrain is usually played in the same style as the first, but sometimes counter-melodies or obbligatos are added to these latter runs of the trio. Now the breakstrain is played again