Is this grammatically correct? Can it be rephrased? What does it mean? “Peter joined me in this ‘ancient oja” sound

The sentence has a small grammatical error due to the quotation marks not being closed properly. It should be corrected to: “Peter joined me in this ‘ancient oja’ sound.” Rephrased, it could be: “Peter participated with me in this sound referred to as ‘ancient oja.’” The meaning of the sentence suggests that Peter and the speaker were together, and they were engaging with or experiencing a sound described as "ancient oja." The term "oja" may refer to something specific, possibly a type of sound, music, or cultural reference, but its exact meaning would depend on context.