your xml is not very good. you can do this:
;with cte_artist as (
select
row_number() over(order by (select '1')) as rn,
T.C.value('text()[1]','varchar(15)') as Artist
from @Data.nodes('/Catalog/Artist/name') as T(C)
), cte_album as (
select
row_number() over(order by (select '1')) as rn,
T.C.value('text()[1]','varchar(15)') as Album
from @Data.nodes('/Catalog/Album/Category') as T(C)
)
select
a1.Artist,
a2.Album
from cte_artist as a1
full outer join cte_album as a2 on a2.rn = a1.rn
But better way would be to create xml like this (or any other nested way you want):
<Catalog>
<Album name="Rock album">
<Category>Rock</Category>
<Artist name="Wolfgang"/>
</Album>
<Album name="Alternative album">
<Category>Alternative</Category>
<Artist name="Razorback"/>
</Album>
</Catalog>
So you could query it like this:
select
T.C.value('@name','varchar(15)') as name,
T.C.value('(Category/text())[1]','varchar(15)') as Category,
T.C.value('Artist[1]/@name','varchar(15)') as Artist
from @Data.nodes('/Catalog/Album') as T(C)