Both  faults  may  be  largely  corrected  by  a
study  of  the  mental  effects  of  the  tones  of
the  scale,  which  is  part  of  the  tonic  sol-fa
-system  (q.v.}  According  to  this  theory,
•when  a  scale  or  tune  is  sounding  in  the
•ear  each  tone  of  it  impresses  the  mind
with  an  individuality  of  its  own.  The
pitch  may  be  high  or  low,  but  the  place  of
the  tone  in  relation  to  its  surrounding
tones  enables  us  to  fix  and  recall  it.  The
singer  who  feels  tones  in  this  way  will
strike  them  with  certainty.  The  ear  or
dictation  exercises,  which  are  another  part
•of  the  tonic  sol-fa  system,  provide  a  second
means  of  rendering  the  ear  sensitive  to
musical  intonation.  From  the  first,  tonic
-sol-fa  pupils  are  taught  not  only  to  pro-
duce sounds  for  given  notes,  but  inversely
to  produce  notes  for  given  sounds.
Singing  sharp  is  a  far  less  common
fault  than  singing  flat.  It  results  from
•excess  of  energy  and  nervous  excitement.
The  causes  of  flattening  are  various,  and
•even  the  best  singers  and  choirs  are  sub-
ject to  it  at  times.  It  may  be  described
;as  generally  due  to  relaxation  of  interest
^ancl  fatigue.  Fresh  air,  change  of  posture,
may  help  to  cure  it.  Sometimes,  if  the
fault  is  bad,  the  singing  should  cease,  and
-some  point  of  theory  which  does  not  in-
volve singing  be  introduced.  It  is  well  to
•accustom  the  class  to  think  about  main-
tenance of  pitch,  even  in  their  unaccom-
panied music,  by  sounding  the  key-note
on  a  chromatic  pitch-pipe  or  the  pianoforte
•at  the  close  as  well  as  at  the  beginning  of


a  piece.  The  wrong  use  of  the  registers,
which  we  have  already  referred  to,  is  also
a  fruitful  cause  of  flattening,  perhaps  the
most  fruitful.
