  Collaborative playlists (CP) enable listeners to curate music together,
translating long-standing social practices around music consumption into the
age of streaming. Yet despite their role in connecting people through music, we
lack an understanding of factors that are critical to CPs and their enjoyment.
To understand what users consider important to CPs and their usage, we
investigated aspects that are perceived to be most useful and lacking in
today's CP implementations. We conducted a survey to collect open-ended text
responses from real-world CP users. Using thematic analysis, we derived the
Codebook of Critical CP Factors, which comprises eight aspects. We gained
insights into which aspects are particularly useful, and which are absent and
desired by current CP users. From these findings we propose design implications
to inform further design of CP functionalities and platforms, and highlight
potential benefits and challenges related to their adoption in current music
services.
