If you're a music fan of a certain age you’ll remember your first Walkman: likely a cassette player with a belt clip and possibly a built-in radio. Long before the smartphone and the iPod, Sony’s player defined portable audio. And it actually never completely disappeared: Last month Sony introduced a new model – a digital music player that promises high-res audio and costs a cool $1200. But how groundbreaking was that original Walkman?

In this week's episode, we ask Robert Klara, a senior editor at Adweek, who recently looked back at this miniature marvel. "The iPod was extremely significant when it debuted in 2001," said Klara, "but it was really the Sony Walkman that ushered in the idea, which was radical at the time, that you could walk around and take your music with you.

"It came with very, very good audio quality plus lightweight headphones, and that was a remarkable thing in 1979 when it hit the market."

But Klara contends that the Walkman become "one of branding's cautionary tales," when the MP3 era arrived and Sony "became complacent." Listen to the full interview above to find out why.

Plus, watch a slideshow of classic Walkman models below, and tell us: What do you remember about your first Walkman (or Discman)?