Vol. IV contains the following titles, which are also offered separately as single edition on SMP and can be found on Youtube:
Irish Fantasy, The Joyful Birdie, Ellyllon, Saint Peter's Postlude, Celtic Hymn, Fanfara alla celtica, Amazing Grace, Under the Starry Sky, Salsamania, Peppiludio, Occitan impression, Irish Delight, Gartan Mother's Lullaby, Variations on "The Gentle Maiden" (Irish Folk tune), Berceuse.
The level of difficulty is different, most of the the lyrical pieces being easier to perform.