After some research, i've found that this track is named 13 (Death March) which was the original title of the movie, and is performed by Jimmy Smith & Wes Montgomery in the Dynamic Duo album in 1966. Don't know if there's an original composition, but i doubt it. As for the soundtrack itself, below i copy/paste the information i've found here (
http://www.dougpayne.com/gmdisco.htm#13).
EYE OF THE DEVIL
Gary McFarland
London: August 1966
Gary McFarland (arr); Jack Parnell (cond) plus members of the London Philharmonic.
a. Main Theme/Philippe�s Study (Gary McFarland) - 4:49
b. Drive to Chateau (Gary McFarland) - 1:00
c. Catherine�s Drive (Gary McFarland) - 1:30
d. Int. Chateau Night/Jacques in Bed (Gary McFarland) - 3:21
e. Odile and Children (Gary McFarland) - 1:21
f. Arrow Into Tree (Gary McFarland) - 1:28
g. Catherine in Chateau at Night/Children on Parapet/Catherine
and Odile on Parapet/Children on Steeple (Gary McFarland) - 5:14
h. Christian Galloping/Horses (Gary McFarland) - 0:50
i. The Grave in the Forest (Gary McFarland) - 5:12
j. Nightmare (Gary McFarland) - 2:34
k. Procession (Gary McFarland) - 3:03
l. Catherine to Tower (Gary McFarland) - 3:34
m. You Must Help Me (Gary McFarland) - 5:30
n. Parapet Pt. 1 (Gary McFarland) - 2:20
o. Parapet Pt. 2 (Gary McFarland) - 2:32
p. Jacques and the Eye (Gary McFarland) - 1:23
q. Trailer (Gary McFarland) - 2:33
Note: (1) The film Eye of the Devil was originally titled 13 when Gary McFarland wrote and recorded this score. Verve Records had intended on issuing a soundtrack album in early 1967 (scheduled as V/V6-8674), and although the album was designed and advertised, production problems which delayed the release of the film stalled the release of the soundtrack until Film Score Monthly finally issued its first-ever release four full decades later, shortly after Deborah Kerr, the last of the film's surviving stars, had passed away. The main theme (titled as such above and below) has also been recorded under other titles, including "13", "Theme from 13", "13 (Death March)", "Eye of the Devil" and, most prominently, as "One I Could Have Loved". McFarland also recorded a theme he originally called "Jacques" (after the son in the film, who will inherit his father's fate - curiously something that was not too dissimilar from what happened between McFarland and his son, Milo) as "Childhood Dreams" with Steve Kuhn on THE OCTOBER SUITE, which can be heard as "Jacques in Bed" above. Here are the titles as they appear in Creed Taylor's production notes for the Verve release and the order of tunes according to the Verve matrix numbers:
1. (101095) Main Theme (Journey) = b
2. (101096) Main Theme (Harp) = a (Main Theme, without intro)
3. (101097) Main Theme (Kids) = c
4. (101098) Death March (Part 1) = m (first half)
5. (101099) Death March (Part 2) = m (second half)
6. (101100) Death March (Part 3) = n
7. (101101) Death March (Part 4) = o
8. (101102) Voices (Ceremony) = d (Int. Chateau Interior)
9. (101103) Main Theme (End) = p
10. (101104) Voices And Bells In Church = k
11. (101105) Christmas Theme = g (Children on Parapet)
12. (101106) Hypnotizing Odillo Theme = g (Catherine and Odile on
Parapet) segue to f (Arrow Into Tree)
13. (101107) Forest Chase = i (last 2:50 only)
14. (101108) Train Ride = q
Additionally, Creed Taylor's production notes and Michel Ruppli's Verve discography indicate the recording dates as November 7 and 8, 1966, which corresponds to when McFarland was in London recording SOFT SAMBA STRINGS. Additionally, Ruppli indicates the presence of Tubby Hayes (f); unknown (p); Lennie Bush (b); Ronnie Stevenson (d) on the November 7 date. The date used above corresponds to the logs that accompanied the tapes provided to Film Score Monthly by M-G-M in England. (Sources: Creed Taylor, Dan Skea, Lukas Kendall). (2) A 16m 33s documentary titled ALL EYES ON SHARON TATE made around the time of EYE OF THE DEVIL utilizes portions of Gary McFarland's music from the film.
Issues: FSM Vol. 11, No. 1 [CD] (originally scheduled as Verve V/V6-8674, but not issued).
Samplers: b & q also on El (E) ACMEM148 [CD] titled SKETCH FOR SUMMER.
Producer: prob. Creed Taylor (Verve V/V6-8674). Lukas Kendall (FSM Vol. 10, No. 18 [CD]).
Engineer: prob. Jack Clegg
Notes: John Bender, Lukas Kendall, Douglas Payne (FSM Vol. 11, No. 1 [CD]).
