Hello Hector, as I see in your signature I think you have an S900, right?
In the Movie & Show Styles folder, there are two special styles for what you want to do, "70sTV Theme" and "SaturdayNight", there is also another very particular style to open a live show and it is "ShowTime"
Listen to these styles completely (with Intros, Variations, and endings) choose the one that is closest to the one you want.
After this you just have to use the quick recording function, and start recording your ideas.
For more information on how to record MIDI sequences, download the S900 PDF manual at the following link.
https://jp.yamaha.com/files/download/other_assets/5/322645/psrs900_en_om_b1.pdfI hope this helps a bit
Cheers
Hans