You are asking, basically, how forgiving is the technology if you miss the beat?

If you are behind the beat the MX arp will assume that is where you wish to be. I'm afraid, just like the real world, it's your responsibility to play the keys on time.

Never use automated technology, like arpeggiators, drum machines, etc, unless everyone in the band can hear them... A common mistake for "second time users" is to attempt to use a device like an Arpeggiator in a situation where only one person is following it. It's like playing in an orchestra where only one violinist is able to see the conductor... It simply is not going to work well. If you think of your automated technology as the "Conductor" then it must be available to all members of the ensemble.

***"Second time users" is a phrase we use for those who try something *once* for both the first and last time. Since it doesn't work the very first attempt, they assume it can't be done, and they give up. I think you have commit, you cannot casually introduce something like an arpeggio or any tempo dependent item to your live set without making sure you give it a really good chance to work. Which usually means a very good floor monitoring or in-ear monitoring system.

When working with just the MX, hold the STOP button and tap the PLAY button to set the Rhythm Pattern (Part 10) to Sync Start, it will now wait for the next KEY ON event to begin play. This way your two ARPs and the Rhythm Pattern will always start and remain together. The Arps and the Rhythm Patterns both reference the MX's internal clock system.

Unfortunately, if playing in a live band, there is no Sync Start and KEY ON event to start the other members of the band. The Play button flashes the tempo, you can count the band in, but it will be imperative that through your monitoring system each member of the band must be able to "see the Conductor" if you get my meaning. If they can't hear your Arps or the tempo that your Arps are referencing, it is only a matter of time before chaos theory takes over!