One of the most accessible of the tunes in William Dixon’s manuscript is the one he titles ‘Ou’r the Dyke & till her Ladey’. (The term ‘dyke-louper’ was used in the Lowlands and Border regions not only for beasts prone to jumping over dry-stone walls but also for ‘a person of immoral habits’).
The title’s appearance in Dixon’s manuscript is not its first, however. There is a version in the Balcarres lute book which is perhaps thirty years before Dixon. This Scottish version is however rather different to Dixon’s, not least for being in an ambiguous mode, hovering as it does between F major and D aeolian.
After Dixon, the title re-appears twice in 18th century collections, one Scottish and two Northumbrian, suggesting that the tune itself was known across the lowland and border region. It does, however take on two distinct forms, both of which appear on both sides of the border.
Here is Dixon’s setting as it appears in the manuscript:

Ou’r the Dyke and till her Ladey; Wm. Dixon Manuscript, 1733 p.66

Here is Dixon’s setting transcribed and transposed to A; in his edition Matt Seattle made some reasonable editorial amendments to the transcription; here I have retained the tune as Dixon pricked it down.
The tune itself is straightforward enough; today we might classify it as a common-time hornpipe, and it responds well to Dick Hensold’s suggestion that the quavers might be swung (or in early 18th century baroque terms, played inégale). At the beginning of the 18th century, when the common-time hornpipe was rare, it may perhaps have been regarded rather as a ‘Scots measure’. (Playford has a ‘New Hornpipe’ in 4/4 in his 1668 collection, though it is an old tune, and the Balcarress Ms also has one, The Galloway Hornpipe.)

Here is my transcription of the tablature in the Balcarres lute book, which originated in the Lindsay family in Fife at the very end of the 17th century. Here the title is ‘Over the dyke and kisse her ladie’. It is pentatonic with a shifting modal centre compared to Dixon’s 3-finger major mode. Nevertheless,  through structure and melodic shape they have much in common in addition to the title (the Balcarres’ compiler often shows this kind of gentility.

‘Over the Dyke, and kisse her ladie. mr Becks way’; Balcarres Lute Book c.1700

The tune appears twice more in 18th century collections. Although they are very similar to each other and thus appear to be derived from a common source, they are rather different to both Balcarres and Dixon. Though both lie within the keyless Northumbrian smallpipe range, they are written in the six-finger key rather than Dixon’s 3-finger key, giving them a ratherdifferent harmonic pattern but never erasing the relationship entirely.

‘O’er the Dyke’ from James Aird’s Airs, Book 5, Glasgow c.1800

‘O’er the Dyke’; A transcription from John Peacock’s Favourite Collection of Tunes, Newcastle, c.1800, the original is in G

Perhaps the mist intriguing of the three post-Dixon versions is that in William Vickers’ fiddle manuscript, dated 1770-1772. In his 2008 edition of the manuscript, Matt Seattle chose to change Vickers’ key signature of one flat to one sharp, adding the following note: “definitely the same tune as [Dixon’s] No. 25 but further investigation (there are similarly titled tunes in Scottish lute sources) may reveal more flexibility.” In his 2011 edition of Dixon’s Manuscript he added, speaking of Vickers’ tune, “this is odd as it stands but if one changes Vickers’ original key signature from one flat to one sharp then his str. 1 is almost identical to Dixon’s. However he goes on to consider the Balcarres setting suggesting that the ‘prevailing mode is similar [to Vickers original] casting some doubt on whether Vickers’ key signature needs changing.” Personally I feel that Vickers original one flat produces a more convincing tune. It seems likely that Dixon’s version has been adapted to fit the pipes from something like the Balcarres tune. Whatever the source for the Aird setting (and it approaches Dixon’s more closely if you start at bar 3) it appears  that Vickers had somehow retained the original modality.

‘Oer The Dyke and At Her’ William Vickers’ manuscript, 1770
(the first two notes in bar 1 should be quavers)

‘Oer The Dyke and At Her’ transcribed into A

Rob MacKillop has recorded the Balcarres version and 80 other tunes from the Balcarres Book: https://scottishlute.files.wordpress.com/2011/12/24-over-the-dyke-and-kisse-her-ladi.mp3