Depends on your needs and budget. I started with a Korg SQ-1 sequencer with my first modular setup then progressed to in rack sequencers. Korg is ok but I much prefer my Eurorack sequencers like Eloquencer, Metron and Stillson Hammer now. I just ordered a new Doepfer 12U Monster case to stack on my Doepfer monster base case and reorganize my modular setup now that I have larger studio space. I probably will wait to end of year to order new mixers, sequencer and few more drum/voice modules plus more utilities like attenuator/attenueverts and so forth. One thing that I learned was to order the BIGGEST case and power you can afford as a beginner as you will quickly grow. I still have my 6u cases to throw a few modules in for jams in town once Covid ends and portable 14U MDLR case but that case is HEAVY and needs a tray to cart around.