The demo tape that came along with the Sony Walkman was probably released around 20 years back. According to my extensive research, I found out that it was named 'Jungle Strut' which was composed by D. Kume and K. Senba. There is not much information available on the net but this is the information that I could sum up for you. There is nothing available about the artists either.
On the demo tape, it is also mentioned something about 'The Square' which is probably the name of the album. It would be quite difficult for you to find the sample on the internet or anywhere else. What you can do is, go to a local electronics shop and enquire about the demo tape. If they have it, they will sell it to you.
In case you do not find it anywhere, you need to go to a Sony Records office in your city and inquire about the same. They might order it for you from the headquarters and sell it to you. This can be a very rare tape so do not keep your hopes up.
On the demo tape, it is also mentioned something about 'The Square' which is probably the name of the album. It would be quite difficult for you to find the sample on the internet or anywhere else. What you can do is, go to a local electronics shop and enquire about the demo tape. If they have it, they will sell it to you.
In case you do not find it anywhere, you need to go to a Sony Records office in your city and inquire about the same. They might order it for you from the headquarters and sell it to you. This can be a very rare tape so do not keep your hopes up.