Songs from her “Sweet 19 Blues” album, which sold more than 3.5 million copies in three months, are heard constantly on the radio.

She is equally ubiquitous on TV. She hosts her own show, sings on music programs, is a frequent guest on variety shows and appears in commercials promoting cassette tapes and beauty parlors. She also just starred in a feature film.

Her popularity can be seen on the streets, where young women dress like her, and heard in the language, where a new word was coined to describe those who copy her style. “Amuraa” refers to young women with golden tans, long hair dyed brown, heavy makeup and short, tight T-shirts.

The Amuraa look is a telling sign of how the genre has shifted focus from the playground to the disco. Idol singers used to be featured mainly for their adolescent looks and persona. Their one and only requirement was to be “kawaii,” or cute.

Seiko Matsuda, the former idol star of the 1980s who still holds the Japanese record with 26 No. 1 hit singles, was typical of the craft. She dressed like a schoolgirl, danced childishly and sang in a pinched voice that was occasionally on-key. Dozens of desperately cute idol singers did much the same, creating a style of pop music that critics considered a travesty.

Amuro, decidedly more funky, has won the grudging respect of the same critics forproving to have some natural ability. She knows how to carry a techno-tune and dance to it at the same time, withmoves that go far beyond the old idols’ limply robotics steps. Yet, even when dancing in skimpy clothes, the new idol projects an image that is young, clean and fun, sexy without the sex, disco for the innocent.

The problem some criticshave is not how but what Amuro sings. To the non-fan it can sound all alike, and suspiciously identical to the bland dance music heard in Italian and Greek discos in the 1980s.

The source is traced back to her producer, Tetsuya Komuro, who turns any act he touches into gold. The 37-year-old former musician at the Avex Trax record company is the reigning kingmaker of Japanese pop. Songs that he writes, arranges and produces are widely expected to sell at least a million units.

When Shin Miyoshi, a Polygram executive, was asked if he knew how to spot a hit song before it reached the charts, he said: “Sure, look for the credit that says ‘Made by Tetsuya Komuro.”‘

The Komuro sound varies little among his various groups. Young idol fans are enthusiastic but not the most discerning buyers. Employing the same British engineers who invented the original Eurobeat, Komuro’s hits have simple, repetitive and catchy melodies sung over a dance beat. The tone is upbeat and ever hopeful. Lyrics may offer inspiring paeans to youthful enjoyment or else nothing at all. Song titles from the first album by globe, an Avex group, are typical. “Give You,” “Feel Like Dance” and “Gonna Be Alright” helped the album sell more than three million units.

Other hit acts from Komuro include Max, a four-girl dance group recruited from the same performing school in Okinawa that produced Amuro, a collection of DJs and dancers known as trf that was popular last year, and Hitomi, adancer who also tries to sing while fronting another Avex techno group.

Foreign music acts have long been popular in Japan, but they can’t match the sales numbers of the current domestic stars. Now in the charts are Van Halen’s “Greatest Hits” (250,000),Los Del Rio’s “Macarena” (140,000) and Kenny G’s “The Moment” (20,000). Japan’s youngest music fans, whose appreciation of pop often starts with an idol singer, prefer to cheer for someone who looks and acts like they do themselves. Or at least how the record companies say they should look and act.

“What an idol needs today,” saysHaruki Tanizaki, Avex PR manager, “is strength. The old image of the cute idol is gone. The dance beat makes a powerful sound so the singers have to be strong to go along with it. They have to be able to sing and dance fairly well.”

Similar idol acts are also selling well, but it is still Amuro who has the industry buzzing. “Because of her,” Mr. Miyoshi of Polygram said, “all the other record companies in Japan are looking for their own idol singers to promote.”

Natural talent is not always the first thing they have in mind. Some of the idols now being promoted are better-dancing echoes of the whiny-voiced singers of the past. Bad singing does not seem to disappoint their fans. It may even do the opposite.

Thanks to the ongoing popularity of karaoke among teens, almost all singles released today also have a sing-along version. This can make the original singer’s version no more than a guide to the melody. The weaker the original voice, the easier it is for the untalented fan to keep up.

Japanese record companies try another marketing tactic not often considered abroad. They tie their hit songs in with trendy TV dramas and commercials aimed at young people.Out of the Top 100 songs now in the charts, 45 are used in TV programs and 24 are heard in commercials.

The resurgence in idol singers is tempting Japanese producers to look beyond the world’s second largest market to buyers abroad. Numerous attempts have been made in the past to export Japanese pop stars, but none has succeeded.

Seiko Matsuda, now in the category of adult female singer, has learned English to advance her career in the West, but it hasn’t worked.

The Japanese version of her latest single went to No. 1 in Japan while the English version flopped in the United States. Despite numerous attempts, no Japanese singer has made it into the Top 40 in the United States since Kyu Sakamoto’s “Suki Yaki” in the 1960s.

So Japanese promoters are looking first to Asia. If Japanese comics and clothes and TV shows can be popular with young people there, they figure, why not pop music?

Amuro’s singles have sold poorly so far in Hong Kong and Taiwan, the two areas thought to be the most idol-friendly, but Avex is planning to release her big album there next month along with an expensive advertising campaign.

A Japanese company called HoriPro has gone to the weirdest lengths so far. Its new idol is Kyoko Date, a 17-year-old from Tokyo who “collects sneakers as a hobby and likes to spend her time learning foreign languages and taking photographs,” according to her handlers, whoadd that she is not, in fact, real.

Kyoko Date is a “virtual idol,” a computer graphic which is supposed to appeal to modern youths who won’t be bothered by her lack of flesh and blood. HoriPro, which says her debut CD will go on sale next month, calls her “the beginning of a new genre of media personalities.”