Quoted from Catholicism.org [1]:
Our Lord remained on earth for forty days after His Resurrection before ascending to His Father. During this time, He appeared twelve times to His Apostles and/or disciples, instructing them, and preparing them for the coming of the Paraclete in His fullness. In the Cenacle, after rising, He appeared to the Apostles and gave them the power of the Holy Ghost so that they could forgive sin....What I found intriguing in the accounts of the Resurrection is that no one believed it until they saw Jesus with their own eyes. And this, even though He had spoken to the Apostles of His passion and resurrection four times. They would not even believe those to whom He had appeared. Our Lord was not pleased; in fact, when He did appear to them all together in the Upper Room “he upbraided them with their incredulity and hardness of heart, because they did not believe them who had seen him after he was risen again” (Mark 16:14).Take Mary Magdalene for example. She, and a few other holy women, saw the empty tomb and two angels, albeit in the form of young men, sitting in the sepulchre. The angels told the women that Jesus is not there, He has risen, as He said He would. Yet, they did not believe the angels, or if they did, it was weakly so. They were in a state of stupor, “for a trembling and fear had seized them.” Mary Magdelene, even after receiving the news from the angel, still asked “the Gardener” who had asked her why she wept (as had the angel also): “Sir, if thou hast taken him hence, tell me where thou hast laid him, and I will take him away” (John 20:15). It was then that Jesus revealed Himself to her.
Quoted from Wikipedia [2]:
Johann Sebastian Bach composed several cantatas and the Ascension Oratorio to be performed in church services on the feast day. He first performed Wer da gläubet und getauft wird, BWV 37, on 18 May 1724, Auf Christi Himmelfahrt allein, BWV 128, on 10 May 1725, Gott fähret auf mit Jauchzen, BWV 43, on 30 May 1726 and the oratorio, Lobet Gott in seinen Reichen, BWV 11, on 19 May 1735.
The J.S. Bach pieces above are available on YouTube.
[2] https://en.wikipedia.org/wiki/Feast_of_the_Ascension#Music, italics original, quoted without hyperlinks.