Hello. Have a look at
Arp
and
Arp 2
Good luck
D

It may be difficult to find the links in the last response.

Arpeggio Making 101 - Part 1
https://yamahasynth.com/learn/montage/mastering-montage-arpeggio-making-101-part-i

Arpeggio Making 101 - Part 2
https://hub.yamaha.com/mastering-montage-arpeggio-making-101-part-ii/

Note that if you edited a big MIDI file down to only a small phrase - and this MIDI file only has 16 or less different notes (different as in MIDI C3 note is different than MIDI C#3 - and not different as in a phrase with C3 1/2 note, C3 16th note, C3 16th note - is 3 notes total but all are C3/not-different so only 1 total "different" notes) - then you should be able to load this into the performance recorder and create an ARP. For exact notes use "fixed" arp type.

Thanks Jason for your reply. Luckily I was able to gather the significance from Arp and Arp2 because I knew the exixtence of those articles. Even though I read out them quite thoroughly, I didn't succeed understanding how to obtain a "custom obbligato" phrase.

Would you please be so kind to elaborate a little more about different and same notes in an arpeggio? What happens if I load - say - a custom arpeggio made up of 16 different values C3 to obtain a 4/4 phrase? Isn't that possible?

An Arp phrase can contain 16 unique Notes. If you are recording a Drum Arp Phrase (Fixed Note Convert Type) the drummer can have a 16-piece Drum Kit.

The Kick Drum on C1 is one unique Note, the Arp phrase could contain hundreds of Kick drum hits.
The Snare Drum on D1 is one unique Note, the Arp phrase could contain hundreds of Smare drum hits,
The Hihats Closed F#1, Pedal G#1, and Open A#1, that’s three unique Notes, the Arp phrase could contain hundreds of Hihat hits.
Each new Drum sound is a unique Note - so again: an Arp Phrase can contain 16 unique Notes... how many times you hit them, is really not important. Above we have just defined 5 unique notes... which I could turn into a 12 bar drum Arp Phrase. If I attempt to add a 17th unique note (a 17th piece to my Kit, it will not sound, period).

Musically speaking, you’ve never counted the unique Notes in a musical phrase... unless you are Arp making why would you.
But 16 unique Notes has a specific meaning that you still seem to be missing.
The
If you are recording an Arp Phrase when you exceed the 16 unique Note limit, your additional Noyptes simply will not sound.
In the example in the article “Mary had a Little Lamb” the verse has four unique Notes... it matters not how many notes are in the entire melody, just that there are four different (unique) musical tones uses... re-mi-do and sol

If your fixed Note Phrase was a chromatic run up the scale from middle C... you could record the 16 notes from C3 to Eb4
Your 16 unique notes can be from anywhere on the keyboard... but the maximum number of unique Note numbers is 16.