For practicing songs, I’m wondering if there’s a way to suppress/omit/mute/silence a recording’s bass guitar. This would allow me to play a bass guitar line myself without hearing the recording’s bass guitar. I could then accompany the recording’s other instruments and vocals. Like karaoke but modified for the bass guitar. Karaoke, as we all know, is an instrumentals-only recording of a song without the vocals, allowing a singer to sing along with a recorded song’s instrumentals in real time. Unlike a karaoke song with its suppressed vocals, you can’t buy a song that’s suppressed a particular musical instrument used in the song such as a bass guitar. As far as I know, suppression can only be done by a recording engineer at the time of recording. If not, can it be done in post-recording and how? I assume it would be done by frequency range. But won’t the song’s vocals also be suppressed? I looked up frequency ranges on google. It looks like vocals overlap some of a bass guitar’s frequency range. A bass guitar’s frequency range is approx. 40-400 Hz (4-string, EADG, fundamental range). Combined male and female voice frequency range is approx. 85-255 Hz.
Unless you have the stems it's difficult to have an unaffected track. Izoptope RX 7 can remove and isolate using the music rebalance feature but at a cost.
A karaoke set would be a useful tool for practicing bass guitar with recorded songs. Unfortunately, as you mentioned, it's not something that's readily available to purchase, and would likely have to be done by a recording engineer at the time of recording. You can check out the software that 풀싸롱 use. They have an audio editing software that can filter out certain frequency ranges, which may be helpful in your case. I would recommend giving it a try and experimenting with different frequency ranges to see if you can find a balance between silencing the bass guitar and not affecting the vocals too much. It may take some trial and error, but it's worth a shot. Let us know how it goes!