Posts for music teachers in Welsh-medium schools were among the hardest to fill last year, with several other secondary subjects attracting two applicants or fewer for each job.
English-medium secondaries fared a little better, with an average 9.6 applications per vacancy, but posts were left unfilled in religious studies, Welsh-second-language, English and physics, according to Assembly government statistics. However, there were plenty of applicants for primary posts, averaging 28.3 and 9.1 respectively in the English and Welsh sectors.
Hundreds of newly-qualified primary teachers are struggling to find work, while secondary schools still have problems recruiting in shortage areas such as sciences and languages.
New recruits in Wales are also failing to respond to changing demand, with applications up a fifth for primary courses but down 1.8 per cent for secondary.
Provisional school census data show Welsh-medium schools advertised seven music posts, received 10 applications and made seven appointments last year. That meant a success rate of 71.4 per cent for applicants. Nine English posts attracted fewer than two applications each. The lone applicant was appointed to the only chemistry job advertised, and no one applied for a design and technology vacancy.
But Welsh-medium secondaries filled more of their 104 vacancies than their English-medium counterparts, which were unable to appoint to 41 of 795 jobs advertised. But they had more choice of candidates, averaging 10.3 applicants per English post.
Betsan Perrett, head of music at Ysgol Bro Morgannwg, Barry, blamed the "dry and old-hat" ways of teaching music for putting pupils off the subject.
"There has been a drop in the number taking music and this is reflected in the number of teachers available. Many qualified teachers are also talented musicians and are lost from the profession when they get their big break in showbusiness."
She added: "Rising numbers of Welsh-medium schools means there is a greater call for Welsh-language music teachers."
Wales is doing better at recruiting new headteachers. A survey, commissioned by the National Association of Head Teachers and the Secondary Heads Association, found more than a fifth of schools in England and Wales failed to make an appointment.
Difficulties appointing senior staff worsened for all schools, with 28 per cent of primary and 20 per cent of secondary schools reporting unfilled head posts after the first round of applications.
But in Wales, only 13 per cent of the 96 schools with senior vacancies had to readvertise. There were, on average, 9.2 applicants for each headship in Wales - compared to 4.2 in London and 5.5 in the rest of England.
The survey drew on more than 3,000 head, deputy and assistant head vacancies advertised between August 2004 and July 2005.
Anna Brychan, director of NAHT Cymru, said: "This survey shows relatively healthy recruitment in Wales. But the figures mask problems in parts, especially rural areas, and members are still concerned about the candidates attracted to management."