Frank Sinatra or Tony Bennett, classical or baroque, early Los Lobos or late: Taste in music seems a deeply personal matter, guided by a person's unique internal compass. But two new studies suggest that social considerations influence not only the music people buy but the recordings they call their favorites.

In one experiment, social scientists at Columbia University simulated an online music marketplace that included 14,341 participants recruited from teenage interest Internet sites. The researchers provided half the group with a list of obscure rock songs and encouraged them to listen and download the ones they liked.

The teenagers received no other information and did not know who else was participating. The songs were a sampling from a Web site where many virtually unknown bands post their own music.

By tallying song downloads, the investigators produced a rough rating of the songs' quality.

When the other half of the teenagers browsed the same songs, they saw, alongside the titles, the number of previous downloads for each song by other members of their group. And they tended to download at least some of the songs previously chosen, resulting in a top 25 chart significantly different from that of the original group.

By running several simulations of this experiment, the researchers showed that song popularity was not at all predictable when people could see what their peers were doing. Good quality songs tended to do better than poorer ones, but not always: a song called "Lockdown" by 52Metro ranked first in one simulation and 40th out of 48 in another.

"A small group of people making decisions at the beginning had a large influence" on how the songs were ultimately ranked, said Duncan Watts, who, along with Matthew Salganik and Peter Sheridan Dodds, reported the findings in the journal Science.

With little else to guide their choices, people often look to others for cues; curiosity, perhaps along with an urge to affiliate with the group creates a kind of cascade effect in favor of the songs first chosen, Dr. Watts said.

In another report, to be published in Psychological Science, psychologists found that people used musical taste as social currency, to read others' personalities and to reveal their own. The researchers paired off 60 students who did not know one another and instructed them to get acquainted via Internet bulletin boards over a period of six weeks.

The students could talk about whatever they wanted, and music was by far the most popular topic, outpacing movies and sports and all other topics five of the six weeks.

To help determine how music taste is related to personality, the psychologists then had a group of 74 students compile a list of their top 10 albums or CD's. One young man's list included the Miles Davis album "Kind of Blue," and Sonic Youth's "NYC Ghosts and Flowers," as well as John Coltrane recordings; another student's list was all country albums; a third's was dominated by hip-hop, with Lil' Bow Wow the top selection.

After listening to the top 10 compilations, eight judges — also students — rated their peers on standard personality profiles. These ratings were remarkably accurate, when compared with the psychologists' own profiles of the 74 participants.

"They did significantly better on some measures than people do when they see pictures or short films of strangers" in similar studies, Peter Rentfrow of Cambridge University in England said in a telephone interview. Samuel Gosling of the University of Texas was a co-author.

The top 10 lists were particularly good in revealing the authors' taste for variety, intellectual appetite for abstract ideas and willingness to experiment with alternative points of view, a quality psychologists call openness. And a high volume of lyrics in a person's list seemed to roughly reflect sociability, or extroversion, Dr. Rentfrow said.

The top 10 lists revealed little, however, about people's levels of conscientiousness — how neat, responsible and organized they were. "This makes some sense," Dr. Rentfrow said. "You can tell more about these kinds of qualities by looking at a picture."