I need help from anyone who remembers and used the old tascam bass trainers. I cut my bass playing teeth using the old CD bass trainers then moved to the MP-BT1. The GTR-1 then followed and now the GB-10 is on the market. I have loved the bass trainers and their functions. However, times have changed. I need to know what the new and current technologies are that do what the old Tascam trainers did. What software or device incrementally slows (or speeds up) music, allows key changes and allows for the bass to be muted and/or eliminated?? I actually still use my BT1 but I need to move to current technology. NO ONE in my area (guitar center techs included) seem to be able to help me. Also, Bass Northwest, The Perfect Bass, Bass San Diego and the Atlanta Bass Gallery are out of business or not brick and mortar stores anymore. Bass Chicago and Bass Central were no help either. I am open to any and all suggestions from the TB community. Thanks in advance.