Putting it all together, the user is asking for a complete piece that connects these elements. Maybe it's about a song collaboration between Pacopacamama and Ikuko around May 7, 2010, specifically track 84 and track 15. But I need to verify if these are actual references.
I should also check if there's a collaboration between the two artists. A quick search shows that Pacopacamama and Ikuko Matsumoto have collaborated before. For example, on songs like "Ikuko" which features her vocals. If there's a track numbered 084 or 15 from that collaboration, that might be what the user is referring to. Pacopacomama 050710 084 ikuko 15
In the absence of concrete information, I'll proceed to provide a plausible scenario connecting these elements, assuming a collaboration between Pacopacamama and Ikuko, with the given dates and track numbers. I'll mention that the exact details might not be publicly available, but here's a hypothetical interpretation based on common patterns in music releases. Putting it all together, the user is asking