Peter Cetera

In the official Chicago video from July 21, 1970, at Tanglewood, Peter Cetera can be seen playing a Fender Precision Bass, which he reportedly acquired in 1969 and used extensively throughout his career with the band.

Peter Cetera played a Gibson EB-3 bass from 1972 to 1975, as seen in the 1973 YouTube video of Chicago performing "Saturday in the Park" and "Does Anybody Really Know What Time It Is?"

Stated on official website

1972 live footage @ 3:41 mark you can clearly see Peter turning and you can see the slotted headstock.

https://www.youtube.com/watch?v=UTFD1C4tVIg

here is other people on Youtube with a similar vintage EB-3L

https://www.youtube.com/watch?v=8ldYhxq8sTA

https://www.youtube.com/watch?v=avMyeCs7Vq0

The "L" at the end of the name is for Long Scale. 34 +1/2 inch.

documentation on the model.

http://www.flyguitars.com/gibson/bass/1971gibsonEB3L.php

http://www.vintageguitarandbass.com/gibson/catalogues/1970_bass_3.php

“I had Pat make a bass and send it to Mike Huckabee, and along the way Pat and I talked about making me a bass, I sort of always liked my white Fender Precision Bass, and so I had him make a Wilkins version.”

Cetera performing during The Under the Stars Summer Arts Festival on July 29, 2017. In this photo he is seen with a Gibson J-45.

Listed on its official website

Throughout this performance of happy man, Peter can be seen with a music man stingray. A clear shot of the instrument can be seen around 2 minutes into the video, with the back of the headstock visible at the start of the clip.