In Dulci Jubilo / On Horseback

Oldfield's "In Dulci Jubilo" is an instrumental version of the German traditional Christmas carol of the same name, known best in England as "Good Christian Men Rejoice". Mike Oldfield had recorded another version with Les Penning of this song as the B-side to his previous single, "Don Alfonso", which did not chart. Later, he felt a better version could be done, and re-recorded it in October 1975 at the Manor, but incorporating some of the previous version's backing tracks recorded November 1974 at the Beacon, his home studio.

The new version features Leslie Penning on two recorders and kortholt, Mike Oldfield on acoustic and electric guitars, piano and ARP string synthesiser, and William Murray on snare drum.[2] Oldfield's decision to re-record the song proved to be a good move; it appeared in Christmas season playlists on radio across Europe, charting at number 4 in the UK,[3] and is one of his most re-issued short songs. It also charted at number 7 in the Irish Singles Chart and at number 3 on the Dutch Top 40.

The song's authorship shown in the track listing below is how it appears on a recent compilation CD. Most editions from the 1970s and 1980s credit it to R. L. Pearsall, arr. Oldfield. Bach and Pearsall both wrote arrangements of it, but the song dates further back than either composer. Italian pressings of the single from 1975 credit it to J. S. Bach.

"On Horseback" features Mike Oldfield on vocals, accompanied by a children's chorus credited as the Penrhos kids. It previously appeared as an untitled song at the end of Oldfield's 1975 album Ommadawn, banded separately but merely listed as part of "Ommadawn Part Two" on the label. The album's liner notes refer to it as "the horse song on side two". Virgin Records recognised this song could also be a contender as a Christmas hit, and was already being played on radio before it was issued as a single; therefore the UK single's label bore a large "A" on each side to encourage radio play of both sides. A large "A" is often used to mark promo records, and copies are often misidentified as promos, but all have this mark.

This record's success as a Christmas single encouraged Oldfield to issue a similar instrumental piece, Portsmouth, the following year.

On 27 July 2012 at the 2012 Summer Olympics opening ceremony Mike Oldfield performed renditions of Tubular Bells, "Far Above the Clouds" and "In Dulci Jubilo" during a segment about the NHS. This rendition appears on the soundtrack album Isles of Wonder.

The piece was also used as the theme tune to the BBC cookery show Fanny Cradock Cooks for Christmas.

A music video was made for this song, and is featured on the DVD Elements – The Best of Mike Oldfield. The video splits the screen up to 9 thumbnail frames, each showing Oldfield or Les Penning playing a different instrument. The music video was directed by Bruce Gowers.