At Pandora, the machine recommendations carry the stamp of a deeper human involvement. Humans examine data and "groom the collection of music" for each listener, according to Chief Scientist Eric Bieschke, speaking at the panel discussion. But that doesn't necessarily preclude the celebrity playlists touted by Beats Music or offered at Spotify, as he told me later in an interview.
"You can't ask a machine why this particular song made you cry," Bieschke said. "There's a place for [celebrity or user playlists]. I don't think it's going away but en masse it's not going to work."
Without more sophisticated algorithms that can efficiently and effectively identify a range of users' tastes at a particular moment or for a particular purpose, playlists can quickly become as cumbersome to deal with as the songs themselves.
Those algorithms, in turn, need to have more accurate information, collected from mobile devices and through tracking usage. Where you are, what the weather is like, the time of day -- all of that can help the machine identify the context of a user's music listening and better enable it to make recommendations.
The goal, as Bieschke put it, is "to connect you and only you with the thing you like to hear."
Scaling the delivery of music to millions of users and yet having the music experience be a personal one is the single greatest ongoing challenge facing the sector and it is multifaceted, with pieces in data collection, pieces in a detailed, musicological analysis of music and pieces in ethnographic and cultural understanding of particular areas.
As an example, Echo Nest CEO Jim Lucchese noted in a private interview that the channels through which songs become popular, the context through which they emerge, can vary in ways that affect streaming selection.
"Things like the fact that people discover popular music in India though film in way that's unique to India, creates an entire new data structure challenge," he said.
At the moment, the industry is relying on western-centered cultural assumptions, but that has to change as an ongoing explosion of digital popular music in Latin American, Asian and African markets is promising to dramatically shift the music industry as a whole. The streaming sector is a pivotal player in that shift: as handheld devices become readily available, some societies with limited Internet access through landlines are skipping past the downloable-digital-file stages experienced in the U.S.'s technological development, leap-frogging directly into streaming over mobile.