Legendary rock band oddly ignored by American books on the origins of alternative metal (7)
I believe the answer is:
adamant
'legendary rock' is the definition.
(I've seen this before)
'band oddly ignored by american books on the origins of alternative metal' is the wordplay.
'oddly ignored' indicates alternate letters.
'by' means one lot of letters go next to another.
'american' becomes 'a' (common abbreviation - e.g. in organisation names).
'books on' becomes 'nt' (New Testament. I am not sure about the 'on' bit.**).
'the origins of' indicates taking the first letters.
The initial letters of 'alternative metal' is 'am'.
The alternating letters of 'band' are 'ad'.
'a'+'nt'='ant'
'ant' put after 'am' is 'amant'.
'ad'+'amant'='ADAMANT'
Can you help me to learn more?
(Other definitions for adamant that I've seen before include "With mind made up" , "Resolute, refusing to yield" , "Unpersuadable" , "Refusing to change one's mind" , "unshakeable in purpose" .)