Reverb (or 'reverberation' in full) is the persistence of sound in a particular space after the original sound is produced. To make the notes blend together, a small amount of reverb is added using the 'RV 7000' device set to 'long hall'. This will simulate the instrument being played, well...in a long hall.
The effect that reverb has on the phrase, is that it makes it quite dreamy and fluffy.
Reverb