If you have a case pending in federal court in Manhattan that involves complicated issues of musical authorship, or you just want to hang out and listen to some cool tunes, Judge Robert W. Sweet is apparently the magistrate you want to draw.

On Tuesday, Judge Sweet ruled in favor of the members of System of a Down in a lawsuit involving their song "B.Y.O.B.” after having heard two competing accounts about the drug-fueled jam sessions that led to its creation and analyzing the music those sessions yielded, The Hollywood Reporter said.

The British publishing company Maxwell Music Limited had sued System of a Down after it was assigned the rights to the works of Casey Chmielinski, who fronts the punk rock band Amen under the name Casey Chaos. In 2002, after Mr. Chmielinski met Daron Malakian, the System of a Down guitarist, the two became friends and began jamming together, sometimes under the influence of illicit substances. Mr. Malakian also signed Mr. Chmielinski to his EatURMusic record label.

But when their friendship soured, Mr. Malakian said, he was owed advance money by Mr. Chmielinski, and Mr. Chmielinski, who said he was offered a 2 percent share of the "B.Y.O.B.” rights for his contributions to the song, wanted more.

After listening to their jams, The Hollywood Reporter said, Judge Sweet ruled that only the first line of the chorus, the opening guitar riff and the bridge section of "B.Y.O.B.” came from the musicians’ collaborative sessions.